Class 10 Science and Math's Solutions Free

Chapter 1 Chemical Reactions and Equations

What is a chemical reaction?

Solution: A chemical reaction is a process in which substances undergo a transformation, resulting in the formation of new substances with different properties.

Explain the difference between physical and chemical changes.

Solution: Physical changes involve altering the state or form of a substance, while chemical changes involve the rearrangement of atoms to form new substances.

Define chemical equation.

Solution: A chemical equation is a concise representation of a chemical reaction using symbols and formulas of the reactants and products.

What are reactants and products in a chemical reaction?

Solution: Reactants are the substances present at the beginning of a chemical reaction, while products are the substances formed after the reaction is complete.

How can you balance a chemical equation?

Solution: To balance a chemical equation, you need to adjust the coefficients in front of the formulas to ensure that the number of atoms of each element is the same on both sides of the equation.

What is a catalyst?

Solution: A catalyst is a substance that increases the rate of a chemical reaction without undergoing any permanent change itself.

List some common examples of redox reactions.

Solution: Rusting of iron, combustion, and photosynthesis are common examples of redox reactions. Question 8: Define exothermic and endothermic reactions. Solution: Exothermic reactions release heat energy to the surroundings, while endothermic reactions absorb heat energy from the surroundings.

What is a displacement reaction?

Solution: A displacement reaction occurs when a more reactive element displaces a less reactive element from its compound.

State the law of conservation of mass.

Solution: The law of conservation of mass states that mass can neither be created nor destroyed during a chemical reaction. The total mass of the reactants is equal to the total mass of the products.

What is the role of a chemical indicator?

Solution: A chemical indicator is a substance that changes color to indicate the presence or absence of certain substances in a solution.

Explain the concept of combination reactions.

Solution: Combination reactions involve the combination of two or more substances to form a single product.

What is a decomposition reaction?

Solution: A decomposition reaction is a type of reaction where a single compound breaks down into two or more simpler substances.

Define precipitation reaction.

Solution: A precipitation reaction is a type of reaction that produces an insoluble solid called a precipitate when two solutions are mixed.

How can you identify whether a chemical reaction has occurred or not?

Solution: The presence of one or more of the following indicators can confirm a chemical reaction: change in color, evolution of gas, formation of a precipitate, change in temperature, or the emission of light.

Explain the concept of neutralization reactions.

Solution: Neutralization reactions occur when an acid reacts with a base to form a salt and water.

What are the main types of chemical reactions?

Solution: The main types of chemical reactions are combination reactions, decomposition reactions, displacement reactions, redox reactions, and acid-base reactions.

Give an example of a combustion reaction.

Solution: Burning of wood or a candle is an example of a combustion reaction, where a substance reacts rapidly with oxygen to release heat and light.

What is meant by the term 'oxidation'?

Solution: Oxidation refers to the process of losing electrons or gaining oxygen during a chemical reaction.

What is meant by the term 'reduction'?

Solution: Reduction refers to the process of gaining electrons or losing oxygen during a chemical reaction.

Explain the concept of corrosion.

Solution: Corrosion is a gradual destruction of metals due to their reaction with environmental factors such as moisture, oxygen, or other substances.

Define the term 'rate of a chemical reaction.'

Solution: The rate of a chemical reaction refers to how fast or slow a reaction occurs with time.

How can you increase the rate of a chemical reaction?

Solution: The rate of a chemical reaction can be increased by increasing temperature, concentration, surface area, or using a catalyst.

What are the factors influencing the speed of a chemical reaction?

Solution: The factors influencing the speed of a chemical reaction include temperature, concentration, particle size, catalysts, and the nature of reactants.

Give an example of an endothermic reaction.

Solution: The reaction between ammonium chloride and water is an example of an endothermic reaction as it absorbs heat from the surroundings.

Define the term 'stoichiometry.'

Solution: Stoichiometry is the calculation of the quantitative relationships between reactants and products in a chemical reaction.

Explain the concept of reversible reactions.

Solution: Reversible reactions are chemical reactions that can proceed in both forward and reverse directions.

State the law of conservation of energy.

Solution: The law of conservation of energy states that energy can neither be created nor destroyed; it can only be transferred or converted from one form to another.

Explain the concept of rate-determining step.

Solution: The rate-determining step is the slowest step in a multistep reaction that determines the overall rate of the reaction.

Define the term 'equilibrium' in a chemical reaction.

Solution: Equilibrium in a chemical reaction refers to a state where the forward and backward reactions are occurring at equal rates, resulting in no net change in the concentration of reactants and products.

What is a reversible reaction in terms of equilibrium?

Solution: In a reversible reaction at equilibrium, the forward and backward reactions are occurring simultaneously with no observable change in the overall concentrations of reactants and products.

What is Le Chatelier's principle?

Solution: Le Chatelier's principle states that when a system at equilibrium is subjected to a change in conditions, it will adjust itself to minimize the effect of that change.

Explain the concept of an autocatalytic reaction.

Solution: An autocatalytic reaction is a chemical reaction where one of the products acts as a catalyst for the reaction.

What are redox reactions? Provide an example.

Solution: Redox reactions are reactions in which there is a transfer of electrons between reactants. An example is the reaction between copper oxide and hydrogen to form copper and water.

Define displacement reactions. Give an example.

Solution: Displacement reactions involve one element displacing another element from its compound. An example is the reaction between zinc and copper sulfate, where zinc displaces copper from copper sulfate to form zinc sulfate and metallic copper.

What is meant by precipitation reactions? Give an example.

Solution: Precipitation reactions occur when two aqueous solutions react to form a solid called a precipitate. An example is the reaction between silver nitrate and sodium chloride, which forms a white precipitate of silver chloride.

What are the effects of temperature on the rate of a chemical reaction?

Solution: Increasing temperature generally increases the rate of a chemical reaction as it provides more energy for reactant particles, leading to more frequent and energetic collisions.

How does concentration affect the rate of a chemical reaction?

Solution: Increasing the concentration of reactants generally increases the rate of a chemical reaction because it increases the number of particles available for collisions.

State the role of a catalyst in a chemical reaction.

Solution: A catalyst increases the rate of a chemical reaction by providing an alternate reaction pathway with lower activation energy, enabling more reactant particles to cross the energy barrier.

How can you represent a chemical reaction using a balanced chemical equation

? Solution: A balanced chemical equation represents a chemical reaction by ensuring that the number of atoms of each element is the same on both sides of the equation, following the law of conservation of mass.

Explain the concept of exothermic reactions. Provide an example.

Solution: Exothermic reactions release heat energy to the surroundings. An example is the reaction between hydrogen and oxygen to form water, which releases a large amount of heat and light.

What are endothermic reactions? Give an example.

Solution: Endothermic reactions absorb heat energy from the surroundings. One example is the reaction between barium hydroxide and ammonium chloride, which absorbs heat from the surroundings, resulting in a decrease in temperature.

Define the term 'oxidation number.'

Solution: Oxidation number is a number assigned to an element in a compound or ion that represents the number of electrons it gains or loses during a chemical reaction.

How can you classify chemical reactions based on the level of complexity?

Solution: Chemical reactions can be classified as simple or complex, depending on the number of reactants involved. Simple reactions involve only two reactants, while complex reactions involve more than two reactants.

What are the conditions required for a chemical reaction to occur?

Solution: For a chemical reaction to occur, reactant particles must collide with sufficient energy and the correct orientation.

Explain the concept of redox titration.

Solution: Redox titration is a method used to determine the concentration of a substance in a solution by carrying out a redox reaction between the substance of interest and a known substance.

Define the term 'chemical equilibrium.'

Solution: Chemical equilibrium is a state in a reversible reaction where the rate of the forward reaction is equal to the rate of the backward reaction, resulting in no net change in the concentrations of reactants and products.

How can you determine the direction of a reversible reaction at equilibrium?

Solution: The equilibrium constant (Keq) can be used to determine the direction of a reversible reaction at equilibrium. If Keq is greater than 1, the reaction favors the products, and if Keq is less than 1, the reaction favors the reactants.

Explain the concept of dynamic equilibrium.

Solution: Dynamic equilibrium is a state of equilibrium where both the forward and backward reactions are occurring at equal rates.

Chapter 2 Acids, Bases, and Salts

Define acids.

Solution 1: Acids are a type of chemical substance that release hydrogen ions (H+) when dissolved in water and have a sour taste.

Name two common acids found in daily life.

Solution 2: Two common acids found in daily life are vinegar (acetic acid) and citrus fruits (citric acid).

What are bases?

Solution 3: Bases are chemical substances that release hydroxide ions (OH-) when dissolved in water and have a bitter taste and soapy feel.

Give two examples of bases.

Solution 4: Two examples of bases are baking soda (sodium bicarbonate) and antacids.

What is the pH scale?

Solution 5: The pH scale is a measure of the acidity or alkalinity of a substance. It ranges from 0 to 14, where 0-6 is acidic, 7 is neutral, and 8-14 is alkaline.

What is the pH value of a neutral substance?

Solution 6: A neutral substance has a pH value of 7.

Define indicators.

Solution 7: Indicators are substances used to determine whether a solution is acidic or basic by displaying different colors at different pH levels.

Give an example of a natural indicator.

Solution 8: An example of a natural indicator is litmus paper, which turns red in an acid and blue in a base.

What is the reaction that takes place when an acid reacts with a metal?

Solution 9: When an acid reacts with a metal, it produces hydrogen gas and a salt.

Write the chemical equation for the reaction between hydrochloric acid and magnesium. Solution 10: 2HCl + Mg ? MgCl2 + H2

What happens when an acid reacts with a base?

Solution 11: When an acid reacts with a base, they neutralize each other, forming salt and water.

Define a salt.

Solution 12: A salt is a compound formed by the neutralization of an acid and a base. It consists of a positive ion (cation) from the base and a negative ion (anion) from the acid.

Give an example of a common salt.

Solution 13: An example of a common salt is sodium chloride (table salt).

What is the importance of salts in our daily life?

Solution 14: Salts have various uses in our daily life, such as food preservation, water softening, medicinal purposes, and making soaps and detergents.

What is the process of making soap called?

Solution 15: The process of making soap is called saponification.

What is the pH value of acid rain?

Solution 16: Acid rain has a pH value less than 5.6.

How does acid rain affect the environment?

Solution 17: Acid rain can damage plants, forests, aquatic life, and buildings due to its corrosive nature.

What is the common name for vitamin C?

Solution 18: The common name for vitamin C is ascorbic acid.

What happens when bases react with metals?

Solution 19: When bases react with metals, they produce hydrogen gas and salt.

Define a strong acid.

Solution 20: A strong acid is an acid that ionizes completely in water, releasing all its hydrogen ions.

What is the pH range of a weak base?

Solution 21: The pH range of a weak base is above 7 but less than 14.

What is the common name for calcium hydroxide?

Solution 22: The common name for calcium hydroxide is slaked lime.

State one use of baking soda at home.

Solution 23: One use of baking soda at home is for neutralizing acid spills.

Define the term "acidic buffer."

Solution 24: An acidic buffer is a solution that helps maintain a constant pH value when small amounts of acid are added to it.

What are antacids used for?

Solution 25: Antacids are used to neutralize excess stomach acid and provide relief from indigestion or heartburn.

Name the acid present in the stinging hair of a nettle leaf.

Solution 26: The acid present in the stinging hair of a nettle leaf is formic acid.

What is the pH value of a strong acid?

Solution 27: The pH value of a strong acid is less than 1.

Name a substance that can be used to neutralize a bee sting.

Solution 28: Baking soda can be used to neutralize a bee sting.

Define litmus solution.

Solution 29: Litmus solution is a purple dye extracted from lichens, used in the form of an aqueous solution as an acid-base indicator.

How does the taste of an acid differ from that of a base?

Solution 30: Acids have a sour taste, while bases have a bitter taste.

What happens when an acid reacts with a metal carbonate?

Solution 31: When an acid reacts with a metal carbonate, it produces salt, water, and carbon dioxide.

State the color changes observed when a red litmus paper is dipped into an acid and a base. Solution 32: When a red litmus paper is dipped into an acid, it turns red. When dipped into a base, it turns blue.

Name the acid present in vinegar.

Solution 33: The acid present in vinegar is acetic acid.

What is the pH value of a weak acid?

Solution 34: The pH value of a weak acid is slightly above 1 but less than 7.

Give an example of a strong base.

Solution 35: Sodium hydroxide (NaOH) is an example of a strong base.

Define the term "alkali."

Solution 36: An alkali is a soluble base that releases hydroxide ions (OH-) when dissolved in water.

What is the taste of an alkali?

Solution 37: Alkalis have a soapy and bitter taste.

Name two substances that can be used as common home antacids.

Solution 38: Two substances that can be used as common home antacids are baking soda and milk of magnesia.

What is the pH value of a strong base?

Solution 39: The pH value of a strong base is greater than 13.

Define the term "neutralization reaction."

Solution 40: A neutralization reaction is a chemical reaction between an acid and a base that results in the formation of salt and water, neutralizing the acidic and basic properties.

Why is rainwater usually acidic?

Solution 41: Rainwater is usually acidic due to the presence of dissolved carbon dioxide (CO2), which forms carbonic acid.

What is the pH range of a weak acid?

Solution 42: The pH range of a weak acid is above 1 but less than 7.

Name the acid present in lemon.

Solution 43: The acid present in lemon is citric acid.

What is the pH value of a neutralization reaction?

Solution 44: The pH value of a neutralization reaction is 7, which is neutral.

State the color changes observed when a blue litmus paper is dipped into an acid and a base.

Solution 45: When a blue litmus paper is dipped into an acid, it turns red. When dipped into a base, it remains blue.

Name the acid present in our stomach.

Solution 46: The acid present in our stomach is hydrochloric acid.

What is the pH value of a weak base?

Solution 47: The pH value of a weak base is slightly above 7 but less than 14.

Give an example of a natural base.

Solution 48: An example of a natural base is baking soda.

What is the common name for sodium bicarbonate?

Solution 49: The common name for sodium bicarbonate is baking soda.

Explain the process of neutralizing a soil with a base.

Solution 50: Neutralizing a soil with a base involves adding a base, such as slaked lime or calcium hydroxide, to reduce the acidity of the soil and make it more suitable for plant growth.

Chapter 3 Metals and Non-metals

Q: Define metals and non-metals.

A: Metals are elements that possess properties like luster, malleability, and ductility. Non-metals lack these properties.

Q: Give some examples of metals and non-metals.

A: Examples of metals include iron, copper, and aluminum. Examples of non-metals include carbon, sulfur, and oxygen.

Q: What is the difference between metals and non-metals based on their physical properties?

A: Metals are generally solid, shiny, and good conductors of heat and electricity, while non-metals can be solid, liquid, or gas, and they are poor conductors of heat and electricity.

Q: How can we determine whether a substance is a metal or a non-metal?

A: This can be determined based on the substance's physical properties like appearance, conductivity, and malleability.

Q: What is reactivity series? Mention a few examples.

A: The reactivity series is a list of metals arranged in the order of their decreasing reactivity. Examples: Potassium, sodium, calcium, etc.

Q: How are metals extracted from their ores?

A: Metals are extracted through processes like reduction, roasting, and electrolysis.

Q: Explain the process of roasting with an example.

A: Roasting is the process of heating an ore in the presence of excess air. For example, zinc oxide is heated to obtain zinc.

Q: What is an alloy? Give an example.

A: An alloy is a mixture of two or more metals or a metal and a non-metal. Example: Brass is an alloy of copper and zinc.

Q: Why are metals good conductors of electricity?

A: Metals have free electrons that can move freely in the metal structure, allowing them to conduct electricity.

Q: What are the uses of metals in daily life?

A: Metals are used in various applications such as making utensils, construction materials, electrical wires, etc.

Q: Why are non-metals bad conductors of electricity?

A: Non-metals do not have free electrons to conduct electricity.

Q: How do non-metals react with oxygen?

A: Non-metals react with oxygen to form oxides. For example, sulfur reacts with oxygen to form sulfur dioxide.

Q: What happens when metal oxides react with acids?

A: Metal oxides react with acids to form salts and water.

Q: Give an example of a reaction where a metal displaces another metal from its salt solution.

A: When iron is added to a copper sulfate solution, it displaces copper and forms iron sulfate.

Q: What are the physical properties of non-metals?

A: Non-metals are generally brittle, dull, and bad conductors of heat and electricity.

Q: What are the uses of non-metals?

A: Non-metals like carbon and sulfur are used in the manufacturing of various chemicals, while non-metals like oxygen and nitrogen are essential for life processes.

Q: What is the importance of metals and non-metals in our daily lives?

A: Metals and non-metals form the basis of various industries, provide materials for construction, and are essential for technological advancements.

Q: Why do metals have high melting and boiling points?

A: Metals have strong metallic bonds between the positive metal ions and the sea of delocalized electrons, which require a lot of energy to break, resulting in high melting and boiling points.

Q: What are the properties of ionic compounds formed between metals and non-metals?

A: Ionic compounds are hard, brittle, and have high melting and boiling points. They can conduct electricity when dissolved in water or molten state.

Q: What are the properties of covalent compounds formed between non-metals?

A: Covalent compounds have low melting and boiling points, are mostly gases, liquids, or low-melting solids, and do not conduct electricity.

Q: How are metals used for corrosion prevention?

A: Metals like zinc and aluminum are often used as sacrificial anodes to prevent other metals from corroding.

Q: Explain the process of electrolysis in the extraction of metals.

A: Electrolysis involves the use of an electric current to decompose a compound into its elements. It is used to extract metals like sodium and aluminum.

Q: Why are metals used for making electric wires?

A: Metals are good conductors of electricity due to their free electrons, making them ideal for making electric wires.

Q: Define mineral.

A: Minerals are naturally occurring substances found in the earth's crust, consisting of one or more elements.

Q: What is the difference between ferrous and non-ferrous metals?

A: Ferrous metals contain iron, like steel, while non-ferrous metals do not, like aluminum or copper.

Q: How are metals classified as per their reactivity with water and dilute acids?

A: Metals are classified as reactive metals and less reactive metals based on their ability to react with water and dilute acids.

Q: Explain the reaction of metals with water.

A: Highly reactive metals like sodium and potassium react vigorously with water to form metal hydroxides and hydrogen gas.

Q: Why do metals not react with nitric acid?

A: Metals do not react with nitric acid because the acid acts as an oxidizing agent, forming a protective oxide layer on the metal surface.

Q: Why does lead not react readily with dilute sulfuric acid? A: Lead is a less reactive metal and reacts slowly with dilute sulfuric acid.

Q: What is the importance of metalloids?

A: Metalloids possess properties of both metals and non-metals. They are used in industries like electronics and semiconductors.

Q: Name a few common metalloids.

A: Silicon, germanium, and arsenic are some common examples of metalloids.

Q: What are the physical properties of metals and non-metals that make them suitable for electrical wiring and insulating purposes?

A: Metals possess high electrical conductivity, while non-metals like rubber and plastic possess insulating properties.

Q: What are oxides? Give an example of a metal oxide.

A: Oxides are compounds formed when oxygen combines with other elements. Example: Iron oxide (Fe2O3).

Q: What property of non-metals makes them suitable for making matchsticks?

A: Non-metals like phosphorus possess the property of ignition and are suitable for making matchsticks.

Q: Define the term 'rusting.'

A: Rusting is the corrosion process that occurs on iron surfaces when they come in contact with moisture and air.

Q: Why do non-metals not displace hydrogen from dilute acids?

A: Non-metals are unable to donate electrons to hydrogen, making them unable to displace it from dilute acids.

Q: State two physical properties that distinguish metals from non-metals.

A: Shiny appearance and high thermal conductivity are physical properties that distinguish metals from non-metals.

Q: Give an example of a metal that is a liquid at room temperature.

A: Mercury is the only metal that exists as a liquid at room temperature.

Q: How do metals react with oxygen in the presence of moisture?

A: Metals react with oxygen in the presence of moisture to form metal oxides. Example: Iron reacts with oxygen to form iron oxide (rust).

Q: What is the process of corrosion?

A: Corrosion is the slow destruction of metals due to the action of moisture, air, and other chemicals.

Q: Why is sodium kept immersed in kerosene oil?

A: Sodium reacts violently with air and moisture. It is stored under oil to protect it from these reactions.

Q: How can we differentiate between metals and non-metals with the help of acids?

A: Most metals react with acids to produce hydrogen gas, while non-metals do not react with acids.

Q: Why is copper used to make electrical wires rather than aluminum?

A: Copper has lower resistance and higher conductivity than aluminum, making it more suitable for making electrical wires.

Q: How do metals react with chlorine?

A: Metals react with chlorine to form metal chlorides. For example, sodium reacts with chlorine to form sodium chloride.

Q: What are the properties of metalloids that make them useful in the semiconductor industry?

A: Metalloids have semiconducting properties, allowing them to be used in the semiconductor industry.

Q: Why do non-metals gain electrons in chemical reactions?

A: Non-metals have a tendency to gain electrons as they have higher electronegativity than metals.

Q: How do non-metals react with water?

A: Non-metals generally do not react with water except for a few highly reactive ones like chlorine and sulfur.

Q: Why do metals usually exist in the solid-state?

A: Metals have strong metallic bonds that require a lot of energy to break, leading to their solid-state at room temperature.

Q: How are the reactivity series and displacement reactions connected?

A: The reactivity series helps predict displacement reactions where a more reactive metal can displace a less reactive metal from its salt solution.

Q: How does the reactivity of metals change as we go down the reactivity series?

A: Generally, as we go down the reactivity series, metals become less reactive.

Chapter 4 Carbon and its Compounds

What is carbon?

Solution: Carbon is an element present in all living organisms and many non-living substances. It forms the basis of organic chemistry.

How many valence electrons does carbon have?

Solution: Carbon has four valence electrons.

Define organic compounds.

Solution: Organic compounds are compounds that contain carbon and hydrogen atoms, along with other elements.

Why is carbon called the 'backbone' of organic compounds?

Solution: Carbon is called the 'backbone' because it can form stable covalent bonds with other carbon atoms, allowing for the formation of large and complex organic molecules.

What is the process of carbon catenation?

Solution: Carbon catenation is the unique property of carbon atoms, where they form long chains or rings by bonding with each other.

Give an example of an organic compound.

Solution: Methane (CH4) is an example of an organic compound.

What is a hydrocarbon?

Solution: Hydrocarbons are organic compounds consisting only of hydrogen and carbon atoms.

Name the three main types of hydrocarbons.

Solution: The three main types of hydrocarbons are alkanes, alkenes, and alkynes.

Define saturated hydrocarbons.

Solution: Saturated hydrocarbons are hydrocarbons that contain only single carbon-carbon bonds.

Provide an example of a saturated hydrocarbon.

Solution: Propane (C3H8) is an example of a saturated hydrocarbon.

Define unsaturated hydrocarbons.

Solution: Unsaturated hydrocarbons are hydrocarbons that contain at least one double or triple carbon-carbon bond.

Provide an example of an unsaturated hydrocarbon.

Solution: Ethene (C2H4) is an example of an unsaturated hydrocarbon.

What is a functional group?

Solution: A functional group is an atom or group of atoms that gives organic compounds their specific chemical properties.

Name the functional group of alcohols.

Solution: The functional group of alcohols is the hydroxyl group (-OH).

Give an example of an alcohol.

Solution: Ethanol (C2H5OH) is an example of an alcohol.

What is an isomer?

Solution: Isomers are compounds with the same molecular formula but different structural or spatial arrangements.

Define esters.

Solution: Esters are organic compounds formed by the condensation reaction between an alcohol and an acid.

Provide an example of an ester.

Solution: Ethyl ethanoate (C4H8O2) is an example of an ester.

What is the process of fermentation?

Solution: Fermentation is a biological process in which sugars are converted into ethanol and carbon dioxide by the action of yeast or bacteria.

Name the greenhouse gas produced by the incomplete combustion of fossil fuels.

Solution: Carbon monoxide (CO) is a greenhouse gas produced by the incomplete combustion of fossil fuels.

Define polymers.

Solution: Polymers are large molecules composed of repeated subunits called monomers.

Give an example of a natural polymer.

Solution: Proteins, found in living organisms, are examples of natural polymers.

What is the difference between addition and condensation polymerization?

Solution: Addition polymerization involves the repetitive addition of monomers without the formation of any by-products, while condensation polymerization involves the elimination of small molecules like water during the polymerization process.

Provide an example of an addition polymer.

Solution: Polyethylene, a common plastic, is an example of an addition polymer.

Define soaps.

Solution: Soaps are sodium or potassium salts of long-chain fatty acids and are used for cleaning purposes.

Explain the process of saponification.

Solution: Saponification is the hydrolysis of fats and oils in the presence of a strong base, resulting in the formation of soap and glycerol.

Name a gas formed when acids react with carbonates or bicarbonates.

Solution: Carbon dioxide (CO2) gas is formed when acids react with carbonates or bicarbonates.

Define synthetic detergents.

Solution: Synthetic detergents are washing agents that have similar properties to soaps but are made from petroleum products.

What are carbon compounds with carbon-to-carbon double bonds called?

Solution: Carbon compounds with carbon-to-carbon double bonds are called alkenes.

Give an example of an alkene.

Solution: Ethene (C2H4) is an example of an alkene.

Define hydrogenation.

Solution: Hydrogenation is the process of adding hydrogen gas to unsaturated compounds, typically carried out in the presence of a catalyst, such as nickel.

Name the process used to convert vegetable oils into fats.

Solution: Hydrogenation is the process used to convert vegetable oils into fats.

What are compounds with triple carbon-carbon bonds called?

Solution: Compounds with triple carbon-carbon bonds are called alkynes.

Give an example of an alkyne.

Solution: Ethyne (C2H2) is an example of an alkyne.

Define addition reactions.

Solution: Addition reactions occur when atoms or groups of atoms are added to the carbon-carbon double or triple bonds, forming single bonds.

Provide an example of an addition reaction.

Solution: Hydrogenation of ethene to form ethane is an example of an addition reaction.

What are functional groups containing a carbon-oxygen double bond called?

Solution: Functional groups containing a carbon-oxygen double bond are called carbonyl groups.

Give an example of a carbonyl compound.

Solution: Acetone (CH3COCH3) is an example of a carbonyl compound.

Define carboxylic acids.

Solution: Carboxylic acids are organic compounds containing the carboxyl functional group (-COOH).

Provide an example of a carboxylic acid.

Solution: Ethanoic acid (CH3COOH) is an example of a carboxylic acid.

What is the process of esterification?

Solution: Esterification is the process of forming an ester by combining an alcohol with an organic acid.

Name the reaction used for the industrial production of esters.

Solution: The reaction used for the industrial production of esters is called Fischer esterification.

Define amines.

Solution: Amines are organic compounds derived from ammonia by replacing one or more hydrogen atoms with alkyl or aryl groups.

What is the functional group of amines?

Solution: The functional group of amines is the amino group (-NH2).

Give an example of an amine.

Solution: Ethylamine (C2H5NH2) is an example of an amine.

What are nitro compounds?

Solution: Nitro compounds are organic compounds that contain a nitro group (-NO2).

Give an example of a nitro compound.

Solution: Nitromethane (CH3NO2) is an example of a nitro compound.

Define haloalkanes.

Solution: Haloalkanes are organic compounds in which one or more hydrogen atoms in an alkane are replaced by halogen atoms.

Provide an example of a haloalkane.

Solution: Chloroethane (C2H5Cl) is an example of a haloalkane.

What is a homologous series?

Solution: A homologous series is a family of organic compounds with similar chemical properties, characterized by the same functional group and a gradual increase in carbon chain length.

Chapter 5 Periodic Classification of Elements

1. What is meant by the periodic classification of elements?

Solution: The arrangement of elements in a systematic manner based on their properties is called periodic classification of elements.

2. Who is known as the father of the periodic table?

Solution: Dmitri Mendeleev is known as the father of the periodic table.

3. What is the atomic number of an element?

Solution: The number of protons present in the nucleus of an atom is known as the atomic number.

4. How are elements arranged in the modern periodic table?

Solution: Elements are arranged in increasing order of atomic number in the modern periodic table.

5. Define periods and groups in the periodic table.

Solution: Periods are horizontal rows in the periodic table, whereas groups are vertical columns.

6. What is the significance of periods in the periodic table?

Solution: Periods indicate the number of electron shells present in an atom.

7. How many periods are there in the modern periodic table?

Solution: There are 7 periods in the modern periodic table.

8. How many groups are there in the modern periodic table?

Solution: There are 18 groups in the modern periodic table.

9. What are valence electrons?

Solution: Valence electrons are the electrons present in the outermost shell of an atom.

10. Why do elements in the same group have similar properties?

Solution: Elements in the same group have similar properties because they have the same number of valence electrons.

11. Why are noble gases called inert gases?

Solution: Noble gases are called inert gases because they have a complete outermost electron shell and show very little chemical reactivity.

12. What is the periodic law?

Solution: The periodic law states that the physical and chemical properties of elements are periodic functions of their atomic numbers.

13. Why do elements in the same period have different properties?

Solution: Elements in the same period have different properties because their number of electron shells and atomic sizes vary.

14. How is the metallic character of an element determined?

Solution: The metallic character of an element increases as we move from right to left and top to bottom in the periodic table.

15. Define the term 'alkali metals.'

Solution: Alkali metals are the elements found in Group 1 of the periodic table, known for their reactivity and tendency to form +1 cations.

16. Give an example of an element from Group 17.

Solution: Chlorine (Cl) is an example of an element from Group 17, also known as the halogens.

17. What are transition elements?

Solution: Transition elements are the elements found in the d-block of the periodic table, characterized by the filling of inner d orbitals.

18. Why do noble gases have very low boiling points?

Solution: Noble gases have very low boiling points because their atoms are held together by weak van der Waals forces.

19. Name three allotropes of carbon.

Solution: Diamond, graphite, and fullerenes are the three allotropes of carbon.

20. How does the atomic size change as we move down a group in the periodic table?

Solution: The atomic size increases as we move down a group in the periodic table.

21. Why do halogens have a high electron affinity?

Solution: Halogens have a high electron affinity because they require only one electron to complete their outermost shell.

22. Which element is known as the "universal solvent"?

Solution: Water (H2O) is known as the "universal solvent."

23. Define the term 'electronegativity.'

Solution: Electronegativity is the measure of the tendency of an atom to attract electrons towards itself.

24. Which element is the best conductor of electricity?

Solution: Silver (Ag) is the best conductor of electricity.

25. Why do non-metals have high ionization energies?

Solution: Non-metals have high ionization energies because they strongly hold onto their valence electrons.

26. What is the significance of hydrogen's position in the periodic table?

Solution: Hydrogen's position in the periodic table is unique because it shares properties with both alkali metals and halogens.

27. Why are alkali metals stored in oil?

Solution: Alkali metals are highly reactive and react with moisture in the air. Storing them in oil prevents their reaction with air and water.

28. Why are metals good conductors of electricity?

Solution: Metals are good conductors of electricity because they have free electrons that can move freely and carry electric charge.

29. Why do alkaline earth metals have higher melting points than alkali metals?

Solution: Alkaline earth metals have higher melting points than alkali metals due to increased metallic bonding caused by the presence of two valence electrons.

30. Define the term 'periodicity.'

Solution: Periodicity refers to the repetition of certain properties at regular intervals in the periodic table.

31. Name two elements with the atomic number less than 5.

Solution: Hydrogen (H) and helium (He) are two elements with atomic numbers less than 5.

32. What is the general electronic configuration of alkali metals?

Solution: The general electronic configuration of alkali metals is ns1.

33. Why are the noble gases chemically inert?

Solution: Noble gases have a completely filled outermost electron shell, which makes them stable and chemically inert.

34. What is the main difference between metals and non-metals?

Solution: Metals generally have high electrical conductivity and luster, while non-metals tend to be brittle and have low electrical conductivity.

35. Define the term 'isotopes.'

Solution: Isotopes are atoms of the same element with the same atomic number but different mass numbers.

36. What is the relationship between the atomic number and the chemical reactivity of elements?

Solution: Generally, the reactivity of elements decreases as we move from left to right across a period and increases as we move down a group.

37. How does the reactivity of halogens change as we move down Group 17?

Solution: The reactivity of halogens decreases as we move down Group 17 in the periodic table.

38. Name two elements that have similar properties to lithium (Li).

Solution: Sodium (Na) and potassium (K) have similar properties to lithium (Li) as they all belong to Group 1 and have one valence electron.

39. Why do noble gases not readily form compounds?

Solution: Noble gases have a complete outermost electron shell, so they do not readily lose, gain, or share electrons to form compounds.

40. What happens when an alkali metal reacts with water?

Solution: When an alkali metal reacts with water, it produces hydrogen gas and an alkaline solution.

41. Name the elements found in the "p-block" of the periodic table.

Solution: Elements from Group 13 to Group 18 are found in the p-block of the periodic table.

42. Why are halogens known as highly reactive non-metals? Solution: Halogens have a strong tendency to gain an electron to complete their outermost shell, leading to their high reactivity.

43. What is the relationship between the atomic number and atomic size?

Solution: Atomic size generally increases as we move from top to bottom in a group and decreases as we move from left to right in a period.

44. Define the term 'noble metals.'

Solution: Noble metals are metals that are resistant to corrosion and oxidation, such as gold, silver, and platinum.

45. What is the significance of the zigzag line in the periodic table?

Solution: The zigzag line in the periodic table separates metals from non-metals and represents the transition elements.

46. What is the difference between metals and metalloids?

Solution: Metals are good conductors of heat and electricity, while metalloids have properties intermediate between metals and non-metals.

47. Why are transition metals often used as catalysts?

Solution: Transition metals have the ability to provide a surface for chemical reactions to occur, making them effective catalysts.

48. What is the general trend of ionization energy in the periodic table?

Solution: Ionization energy generally increases as we move from left to right across a period and decreases as we move down a group.

49. Why do alkali metals have a low ionization energy?

Solution: Alkali metals have a low ionization energy because their valence electron is far from the nucleus, making it easier to remove.

50. What are halides?

Solution: Halides are compounds formed by the combination of halogens with other elements, such as sodium chloride (NaCl) and potassium iodide (KI).

Chapter 6 Life Processes

Q1: What is the process by which living organisms obtain and utilize energy?

A1: The process by which living organisms obtain and utilize energy is known as metabolism.

Q2: Name the type of nutrition exhibited by plants.

A2: Plants exhibit autotrophic nutrition as they can produce their own food using sunlight, water, and carbon dioxide.

Q3: What is the function of chlorophyll in plants?

A3: Chlorophyll is a green pigment present in plants that absorbs sunlight for photosynthesis, the process of converting light energy into chemical energy.

Q4: What are the two types of nutrition in animals?

A4: Animals exhibit heterotrophic nutrition, which can be divided into two types: saprophytic and holozoic.

Q5: Define saprophytic nutrition.

A5: Saprophytic nutrition refers to the mode of nutrition in which organisms obtain nutrients by decomposing dead and decaying organic matter.

Q6: What is the process by which plants release excess water in the form of vapor?

A6: The process by which plants release excess water in the form of vapor is called transpiration.

Q7: Name the process by which green plants prepare their own food.

A7: The process by which green plants prepare their own food is called photosynthesis.

Q8: What is the role of respiration in living organisms?

A8: Respiration is the process by which living organisms obtain energy by breaking down food molecules. It provides energy for various life processes.

Q9: Define excretion.

A9: Excretion is the process of removing waste materials, such as carbon dioxide, urine, and sweat, from the body of an organism.

Q10: Name the organs responsible for excretion in humans.

A10: The kidneys, lungs, and skin are the main organs responsible for excretion in humans.

Q11: What is the function of stomata in plants?

A11: Stomata are tiny openings present on the surface of leaves. They help in the exchange of gases, allowing carbon dioxide to enter and oxygen to exit the plant.

Q12: What is digestion?

A12: Digestion is the process of breaking down complex food substances into simpler forms that can be absorbed and utilized by the body.

Q13: Name the enzyme present in saliva that helps in the digestion of starch.

A13: The enzyme present in saliva that helps in the digestion of starch is called amylase.

Q14: What is the main function of the circulatory system?

A14: The main function of the circulatory system is to transport oxygen, nutrients, hormones, and waste products throughout the body.

Q15: Define respiration in plants.

A15: Respiration in plants is the process of breaking down glucose to release energy for various metabolic activities.

Q16: Name the green pigment present in plants that allows them to capture sunlight.

A16: The green pigment present in plants that allows them to capture sunlight is chlorophyll.

Q17: What is the role of the liver in the process of digestion?

A17: The liver produces bile, which helps in the breakdown and digestion of fats.

Q18: Name the process by which excess carbon dioxide is removed from the body.

A18: The process by which excess carbon dioxide is removed from the body is called exhalation.

Q19: What is the role of the small intestine in digestion?

A19: The small intestine is responsible for the absorption of digested food molecules into the bloodstream.

Q20: Name the process by which food is broken down by the action of enzymes in the stomach.

A20: The process by which food is broken down by the action of enzymes in the stomach is called digestion.

Q21: Define osmosis.

A21: Osmosis is the movement of water molecules from an area of higher concentration to an area of lower concentration through a semi-permeable membrane.

Q22: Name the largest artery in the human body.

A22: The largest artery in the human body is called the aorta.

Q23: What is the function of the diaphragm in the respiratory system?

A23: The diaphragm is a muscle that separates the chest cavity from the abdominal cavity. It plays a crucial role in the process of breathing by contracting and relaxing.

Q24: Define aerobic respiration.

A24: Aerobic respiration is a process that occurs in the presence of oxygen and involves the breakdown of glucose to produce energy, carbon dioxide, and water.

Q25: Name the waste product excreted by the kidneys.

A25: The waste product excreted by the kidneys is urine.

Q26: What is the role of the nervous system in the body?

A26: The nervous system is responsible for coordinating and controlling the activities of different parts of the body.

Q27: Define fertilization.

A27: Fertilization is the process in which a sperm cell and an egg cell fuse to form a zygote, which develops into an offspring.

Q28: Name the process by which green plants obtain nitrogen from the soil.

A28: The process by which green plants obtain nitrogen from the soil is called nitrogen fixation.

Q29: What is the function of the blood in our body?

A29: Blood transports oxygen, nutrients, hormones, and waste products throughout the body. It also helps in maintaining the body's temperature and pH balance.

Q30: Define photosynthesis.

A30: Photosynthesis is the process by which green plants convert sunlight, carbon dioxide, and water into glucose (food) and oxygen.

Q31: Name the pigment responsible for carrying oxygen in the red blood cells.

A31: The pigment responsible for carrying oxygen in the red blood cells is called hemoglobin.

Q32: What is the function of the respiratory system in the human body?

A32: The function of the respiratory system is to exchange gases, taking in oxygen and expelling carbon dioxide.

Q33: Define diffusion.

A33: Diffusion is the movement of particles (solutes) from an area of higher concentration to an area of lower concentration to establish equilibrium.

Q34: Name the process by which plants prepare food in the absence of sunlight.

A34: The process by which plants prepare food in the absence of sunlight is called chemosynthesis.

Q35: What is the role of the large intestine in digestion?

A35: The large intestine absorbs water from undigested food and forms and eliminates feces.

Q36: Define locomotion.

A36: Locomotion is the ability of an organism to move from one place to another.

Q37: Name the process by which plants lose excess water through specialized openings.

A37: The process by which plants lose excess water through specialized openings called hydathodes is called guttation.

Q38: What is the function of the kidneys in the excretory system?

A38: The kidneys filter waste products, excess water, and toxins from the blood, producing urine for excretion.

Q39: Define tropism.

A39: Tropism is a growth or movement response of a plant to external stimuli, such as light, gravity, or touch.

Q40: Name the process that occurs in plants to convert nitrate into useful nitrogen compounds.

A40: The process that occurs in plants to convert nitrate into useful nitrogen compounds is called assimilation.

Q41: What is the role of saliva in digestion?

A41: Saliva helps in the moistening and initial breakdown of food, making it easier to swallow and digest.

Q42: Define homeostasis.

A42: Homeostasis is the ability of an organism to maintain stable internal conditions despite external changes.

Q43: Name the process by which food is masticated (chewed) in the mouth.

A43: The process by which food is masticated (chewed) in the mouth is called mechanical digestion.

Q44: What is the role of the pancreas in digestion?

A44: The pancreas produces digestive enzymes that help in the breakdown of carbohydrates, proteins, and fats.

Q45: Define anaerobic respiration.

A45: Anaerobic respiration is a process that occurs in the absence of oxygen and involves the breakdown of glucose to produce energy and lactic acid or ethanol (alcohol).

Q46: Name the organ where urine is stored before elimination.

A46: Urine is stored in the urinary bladder before elimination through the urethra.

Q47: What is the function of blood vessels in the circulatory system?

A47: Blood vessels (arteries, veins, and capillaries) carry and transport blood to different parts of the body.

Q48: Define autotrophic nutrition.

A48: Autotrophic nutrition is the ability of an organism to produce its own food using simple inorganic substances.

Q49: Name the process by which excess water is eliminated from the human body.

A49: The process by which excess water is eliminated from the human body is called urination.

Q50: What is the role of the skeletal system in the human body?

A50: The skeletal system provides support, protection to vital organs, produces blood cells, and allows movement through its bones and joints.

Chapter 7 Control and Coordination

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Chapter 8 How do Organisms Reproduce?

Q: What is reproduction?

A: Reproduction is the biological process through which new individuals of the same species are produced.

Q: Name the two main types of reproduction.

A: The two main types of reproduction are asexual reproduction and sexual reproduction.

Q: Define asexual reproduction.

A: Asexual reproduction involves the production of offspring from a single parent without the involvement of gametes (reproductive cells).

Q: Give an example of asexual reproduction.

A: Budding in yeast is an example of asexual reproduction.

Q: Define sexual reproduction.

A: Sexual reproduction involves the fusion of male and female gametes to produce offspring.

Q: Give an example of sexual reproduction.

A: The reproduction in humans is an example of sexual reproduction.

Q: What are gametes?

A: Gametes are the reproductive cells with half the number of chromosomes present in the body cells.

Q: Differentiate between asexual and sexual reproduction.

A: Asexual reproduction involves a single parent and produces identical offspring, while sexual reproduction involves two parents and produces genetically diverse offspring.

Q: Name the male and female reproductive organs in humans.

A: The male reproductive organ is the testes, while the female reproductive organ is the ovaries.

. Q: What is fertilization?

A: Fertilization is the process in which the male and female gametes fuse to form a zygote.

. Q: Where does fertilization take place in humans?

A: Fertilization takes place in the fallopian tubes of a female.

. Q: Define the menstrual cycle.

A: The menstrual cycle is a monthly cycle experienced by females that involves the shedding of the uterine lining and the release of an egg.

. Q: What is menstruation?

A: Menstruation is the monthly process of shedding the uterine lining and is marked by vaginal bleeding.

. Q: What is ovulation?

A: Ovulation is the process of releasing a mature egg from the ovaries.

. Q: How many eggs are produced during human ovulation?

A: Generally, only one egg is released during human ovulation.

. Q: What is the gestation period?

A: The gestation period is the duration of pregnancy from fertilization until birth.

. Q: How long is the gestation period in humans?

A: The gestation period in humans is approximately nine months.

. Q: Define a zygote.

A: A zygote is a fertilized egg that results from the fusion of male and female gametes.

. Q: What is cleavage?

A: Cleavage is the process of rapid cell divisions that occur in the zygote after fertilization.

. Q: What are identical twins?

A: Identical twins are formed when a single zygote splits into two separate embryos.

. Q: What are fraternal twins?

A: Fraternal twins are formed when two different eggs are fertilized by two separate sperm cells.

. Q: What is puberty?

A: Puberty is the stage of life when an individual becomes capable of sexual reproduction.

. Q: What is adolescence?

A: Adolescence refers to the transitional period between childhood and adulthood.

. Q: What is a primary sex organ?

A: Primary sex organs are the organs directly involved in the production of gametes (testes in males and ovaries in females).

. Q: Define secondary sexual characteristics.

A: Secondary sexual characteristics are physical features that appear during puberty and help in distinguishing between males and females (e.g., facial hair in males, breast development in females).

. Q: What are the advantages of asexual reproduction?

A: Advantages of asexual reproduction include rapid reproduction, no need for a mate, and the ability to colonize new habitats quickly.

. Q: What are the advantages of sexual reproduction?

A: Advantages of sexual reproduction include genetic variation, improved adaptation to changing environments, and the elimination of harmful genetic traits.

. Q: What is regeneration?

A: Regeneration is the ability of an organism to replace lost or damaged body parts.

. Q: Provide an example of regeneration.

A: The ability of a lizard to regrow its tail after it has been severed is an example of regeneration.

. Q: Define spore formation.

A: Spore formation is a method of asexual reproduction in which specialized cells called spores are produced by the parent organism.

. Q: Give an example of spore formation.

A: The formation of spores in fungi is an example of spore formation.

. Q: What is fragmentation?

A: Fragmentation is a form of asexual reproduction where a parent organism breaks into two or more parts, and each part grows into a new organism.

. Q: Provide an example of fragmentation.

A: The process of a single parent Hydra breaking into multiple parts, each developing into a new Hydra, is an example of fragmentation.

. Q: What is binary fission?

A: Binary fission is a type of asexual reproduction in which a parent organism divides into two equal-sized daughter cells.

. Q: Give an example of binary fission.

A: The process of bacterial cells dividing into two daughter cells is an example of binary fission.

. Q: What is budding?

A: Budding is a form of asexual reproduction in which a small outgrowth (bud) forms on the parent organism, eventually detaches, and grows into a new organism.

. Q: Provide an example of budding.

A: The reproduction of yeast through budding is an example of budding.

. Q: Define vegetative propagation.

A: Vegetative propagation is a type of asexual reproduction in plants where new individuals are produced from vegetative parts like stems, leaves, or roots.

. Q: Give an example of vegetative propagation.

A: The process of growing new plants from plant cuttings is an example of vegetative propagation.

. Q: What is pollination?

A: Pollination is the transfer of pollen grains from the male reproductive organ (stamen) to the female reproductive organ (pistil) in flowering plants.

. Q: What is self-pollination?

A: Self-pollination is the transfer of pollen from the stamen to the pistil of the same flower or another flower on the same plant.

. Q: What is cross-pollination?

A: Cross-pollination is the transfer of pollen from the stamen of one flower to the pistil of another flower on a different plant of the same species.

. Q: What is the significance of cross-pollination?

A: Cross-pollination helps in the exchange of genetic material between different individuals, leading to genetic variation.

. Q: What is an embryo?

A: An embryo is the early stage of a multicellular organism that develops from a fertilized egg.

. Q: What are the three main parts of a seed?

A: The three main parts of a seed are the embryo, endosperm, and seed coat.

. Q: Define dispersal.

A: Dispersal is the process by which seeds, fruits, or spores are carried away from the parent plant to new locations.

. Q: Name the agents involved in seed dispersal.

A: Agents involved in seed dispersal include wind, water, animals, and explosive mechanisms.

. Q: What is germination?

A: Germination is the process in which a seed develops into a new plant under suitable conditions.

. Q: What are the basic requirements for germination?

A: The basic requirements for germination are water, oxygen, and suitable temperature.

. Q: Why is reproduction essential for the survival of a species?

A: Reproduction is essential for the survival of a species as it ensures the continuation of the species by producing new individuals and maintaining genetic diversity.

Chapter 9 Heredity and Evolution

Question: What is heredity?

Solution: Heredity refers to the passing of genetic information from parents to offspring.

Question: How are traits inherited?

Solution: Traits are inherited through genes, which are pieces of DNA passed down from parents to children.

Question: What is a gene?

Solution: A gene is a segment of DNA that carries the instructions for a specific trait.

Question: What is an allele?

Solution: An allele is a variant form of a gene that determines a specific trait.

Question: How do dominant and recessive traits interact?

Solution: Dominant traits are expressed when at least one dominant allele is present, while recessive traits are only expressed when two recessive alleles are present.

Question: What is the difference between genotype and phenotype?

Solution: Genotype refers to the genetic makeup of an organism, while phenotype refers to the physical characteristics or traits that are expressed.

Question: How do variations occur in a population?

Solution: Variations occur through genetic mutations, genetic recombination during reproduction, and environmental factors.

Question: What is natural selection?

Solution: Natural selection is the process by which certain traits become more or less common in a population based on their ability to survive and reproduce.

Question: What is evolution?

Solution: Evolution is the gradual change in the inherited characteristics of a population over successive generations.

. Question: What are fossils?

Solution: Fossils are the preserved remains or traces of ancient organisms that provide evidence of past life forms.

. Question: How do fossils help in studying evolution?

Solution: Fossils provide valuable evidence of past life forms and their characteristics, allowing scientists to study the history and development of different species.

. Question: What is genetic variation?

Solution: Genetic variation refers to the diversity of genes within a population, resulting in different traits and characteristics among individuals.

. Question: How does selective breeding contribute to evolution?

Solution: Selective breeding, also known as artificial selection, involves humans intentionally breeding organisms with desirable traits. Over time, this can lead to the evolution of new varieties or breeds.

. Question: What is genetic engineering?

Solution: Genetic engineering is the process of manually manipulating an organism's DNA to introduce desired traits or modify existing ones.

. Question: Explain the role of mutations in evolution.

Solution: Mutations are random changes in an organism's genetic material. Beneficial mutations can provide an advantage, allowing organisms to adapt and survive better in their environment, thus contributing to evolution.

. Question: How does the environment influence evolution?

Solution: Environmental factors such as availability of resources, predation, and climate can exert selective pressure on organisms, leading to adaptations and changes in the population over time.

. Question: What is speciation?

Solution: Speciation is the process by which new species arise from existing species due to the accumulation of genetic changes and reproductive isolation.

. Question: What is genetic drift?

Solution: Genetic drift refers to random changes in the gene pool of a small population due to chance events, such as natural disasters, leading to a loss of genetic diversity.

. Question: What is coevolution?

Solution: Coevolution occurs when two or more species influence each other's evolution through mutual interactions, such as predator-prey relationships or symbiotic associations.

. Question: Provide an example of a homologous structure.

Solution: The forelimbs in humans, bats, whales, and birds are all examples of homologous structures, as they share a common origin but have different functions.

. Question: What is genetic recombination?

Solution: Genetic recombination occurs during sexual reproduction when DNA from two parent organisms is mixed to produce offspring with a unique combination of genes.

. Question: Explain the concept of adaptive radiation.

Solution: Adaptive radiation refers to the diversification of a single ancestral species into a variety of different species, each adapted to a specific environment or niche.

. Question: What is the role of mutations in genetic diversity?

Solution: Mutations are a primary source of genetic diversity in populations as they introduce new genetic variations that can be acted upon by natural selection.

. Question: How does Lamarck's theory of inheritance differ from Darwin's theory of evolution?

Solution: Lamarck's theory proposed that acquired traits could be passed on to offspring, while Darwin's theory focused on natural selection acting on inherited traits.

. Question: What is genetic equilibrium?

Solution: Genetic equilibrium occurs when the frequency of alleles in a population remains constant from generation to generation, indicating a lack of evolutionary change.

. Question: How does the study of DNA support the theory of evolution?

Solution: DNA analysis allows scientists to compare and trace the relationships between different species, shedding light on their evolutionary history and common ancestry.

. Question: What is a gene pool?

Solution: A gene pool refers to all the genes, including different alleles, present within a population.

. Question: Explain the concept of convergent evolution.

Solution: Convergent evolution occurs when unrelated species evolve similar traits or characteristics due to similar environmental pressures.

. Question: What is the significance of the Peppered moth experiment in understanding natural selection?

Solution: The Peppered moth experiment demonstrated how changes in the environment, such as pollution, led to differential survival rates of moth variants, providing evidence for natural selection in action.

. Question: Describe the process of artificial selection.

Solution: Artificial selection involves selectively breeding organisms with specific traits to produce offspring with those desired traits. This process is often used in agriculture and animal breeding.

. Question: What is biotechnology?

Solution: Biotechnology is the use of living organisms or their components to develop useful products or solve problems.

. Question: How are fossils formed?

Solution: Fossils are formed when the remains or traces of dead organisms are preserved in sedimentary rock layers over long periods of time.

. Question: Define genetic counseling.

Solution: Genetic counseling is a process where individuals or families with a history of genetic disorders consult with healthcare professionals to understand the risks and make informed decisions about their genetic health.

. Question: Explain the process of genetic recombination during meiosis.

Solution: Genetic recombination occurs during meiosis when pairs of homologous chromosomes exchange genetic material, resulting in the formation of genetically diverse sex cells (gametes).

. Question: What are vestigial organs?

Solution: Vestigial organs are structures in organisms that have lost their original function through evolution. Examples include the human appendix and the wings of flightless birds.

. Question: Describe the principles of Lamarck's theory of evolution.

Solution: Lamarck proposed that traits acquired during an organism's lifetime could be inherited by the next generation, leading to progressive changes over time.

. Question: What is the significance of the theory of natural selection?

Solution: The theory of natural selection explains how species adapt and evolve over time in response to changes in their environment, leading to the diversity of life forms we observe today.

. Question: Explain the concept of genetic linkage.

Solution: Genetic linkage refers to the tendency of genes located close to each other on the same chromosome to be inherited together more frequently during reproduction.

. Question: What is the role of mutation and recombination in creating genetic variations within a population?

Solution: Mutations provide new genetic variations, while genetic recombination shuffles existing genetic material, contributing to genetic diversity within a population.

. Question: How do variations in a population provide a selective advantage?

Solution: Variations provide a diverse range of traits within a population. Some traits may provide a selective advantage in a given environment, increasing an individual's chances of survival and reproduction.

. Question: Explain the concept of speciation through geographical isolation.

Solution: Geographical isolation occurs when a physical barrier separates a population, preventing gene flow. Over time, genetic differences accumulate, leading to the formation of new species.

. Question: What is the significance of the study of DNA sequences in understanding evolutionary relationships?

Solution: DNA sequences provide molecular evidence that can be used to determine the relatedness or evolutionary relationships between different species and estimate when common ancestors existed.

. Question: How does antibiotic resistance in bacteria support the theory of evolution?

Solution: Antibiotic resistance in bacteria is an example of how organisms can evolve and adapt to survive in changing environments. It demonstrates the process of natural selection acting on heritable traits.

. Question: What is the concept of adaptive features?

Solution: Adaptive features are traits or characteristics that help an organism survive and reproduce in its specific environment. These traits are favored by natural selection.

. Question: Explain the term "survival of the fittest."

Solution: Survival of the fittest refers to the concept that individuals with traits best suited for their environment will have a higher chance of surviving, reproducing, and passing on their genes to future generations.

. Question: What is genetic pollution?

Solution: Genetic pollution refers to the unintended spread of genetically modified organisms into the wild, potentially affecting natural ecosystems and genetic diversity.

. Question: How does the study of comparative anatomy provide evidence for evolution?

Solution: Comparative anatomy involves comparing the anatomical structures of different organisms. Similarities in bone structure or organ placement suggest a common ancestry and support the theory of evolution.

. Question: What is the relationship between DNA and protein synthesis?

Solution: DNA contains the instructions for building proteins. During protein synthesis, DNA is transcribed into RNA, which is then translated into the sequence of amino acids that make up proteins.

. Question: Describe the mechanisms of genetic inheritance.

Solution: Genetic inheritance occurs through the transmission of genes from parents to offspring. This can happen through both sexual reproduction and asexual reproduction.

. Question: How can the study of heredity and evolution have practical applications in various fields?

Solution: The study of heredity and evolution has practical applications in fields such as agriculture, medicine, and conservation. It helps in breeding highyield crops, understanding genetic diseases, and conserving endangered species.

Chapter 10 Light: Reflection and Refraction

What is light?

Solution: Light is a form of energy that enables us to see objects around us.

Define reflection.

Solution: Reflection is the bouncing back of light when it hits a surface.

What is the law of reflection?

Solution: The law of reflection states that the angle of incidence is equal to the angle of reflection.

Describe the types of reflection.

Solution: The types of reflection are regular reflection, where a parallel beam of light reflects uniformly, and irregular reflection, where light scatters randomly.

Explain the terms incident ray, reflected ray, and normal.

Solution: The incident ray is the incoming ray of light, the reflected ray is the ray that bounces back, and the normal is the perpendicular line to the reflecting surface.

What is a virtual image?

Solution: A virtual image is an image formed by the apparent intersection of light rays. It cannot be projected on a screen.

Define real image.

Solution: A real image is an image formed by actual intersection of light rays. It can be projected on a screen.

How can you observe an image in a plane mirror?

Solution: You can observe an image in a plane mirror by viewing it from the front.

Explain the term lateral inversion.

Solution: Lateral inversion is the phenomenon where a mirror reverses the left and right orientation of an object.

. What is refraction?

Solution: Refraction is the bending of light when it passes from one medium to another, due to a change in its speed.

. Describe the terms refracted ray and refractive index.

Solution: The refracted ray is the ray of light that bends after passing through a medium. Refractive index is the measure of how much a medium can bend light.

. What happens to the speed of light when it enters a denser medium?

Solution: When light enters a denser medium, its speed decreases.

. Explain total internal reflection.

Solution: Total internal reflection occurs when the angle of incidence is greater than the critical angle, causing the light to be fully reflected back into the denser medium.

. Define the critical angle.

Solution: The critical angle is the angle of incidence that results in an angle of refraction of 90 degrees.

. How is a prism used to split white light into its constituent colors?

Solution: A prism is used to split white light into its constituent colors by refracting each color at a slightly different angle due to varying wavelengths.

. What is dispersion of light?

Solution: Dispersion of light refers to the splitting of white light into its constituent colors.

. Explain the formation of a rainbow.

Solution: A rainbow is formed when sunlight is refracted, reflected, and dispersed by water droplets in the atmosphere, creating a spectrum of colors.

. How does the human eye perceive objects around us?

Solution: The human eye perceives objects by receiving light that reflects off them and forms an image on the retina, which is then transmitted to the brain.

. What is the focal length of a lens?

Solution: The focal length of a lens is the distance between its optical center and the principal focus.

. Describe the difference between a convex and concave lens.

Solution: A convex lens is thicker at the center and converges incoming light rays, while a concave lens is thinner at the center and diverges incoming light rays.

. What are the uses of a convex lens?

Solution: A convex lens is used in microscopes, cameras, and glasses to correct long-sightedness (hypermetropia).

. Explain nearsightedness (myopia).

Solution: Nearsightedness (myopia) is a condition where a person can see nearby objects clearly but has difficulty seeing distant objects due to the image being focused in front of the retina.

. Describe farsightedness (hypermetropia).

Solution: Farsightedness (hypermetropia) is a condition where a person can see distant objects clearly but has difficulty focusing on nearby objects due to the image being focused behind the retina.

. How is corrective lens used to address myopia and hypermetropia?

Solution: A concave lens is used to correct myopia (nearsightedness) by diverging incoming light rays. A convex lens is used to correct hypermetropia (farsightedness) by converging incoming light rays.

. What is the power of a lens?

Solution: The power of a lens is the reciprocal of its focal length, measured in diopters.

. Define the term scattering of light.

Solution: Scattering of light refers to the phenomenon where light is deflected in different directions as it interacts with particles or irregularities in a medium.

. What causes the sky to appear blue?

Solution: The sky appears blue because of Rayleigh scattering, where the shorter blue wavelengths of light are scattered more compared to longer wavelengths.

. Why do objects appear non-transparent when light is incident on them?

Solution: Objects appear non-transparent when light is incident on them because they absorb or reflect most of the light rather than transmitting it.

. How does the color of an object appear under white light?

Solution: The color of an object appears as the color it reflects and does not absorb. For example, a red object appears red because it reflects red light.

. Explain the terms translucent, transparent, and opaque.

Solution: Translucent objects allow some light to pass through but scatter it in different directions. Transparent objects allow light to pass through without significant scattering. Opaque objects do not allow light to pass through.

. Describe the process of vision in the human eye.

Solution: The process of vision begins when light enters the eye through the cornea, then passes through the pupil and the lens, which focuses the light onto the retina. The retina converts light into electrical signals that travel to the brain through the optic nerve, leading to the perception of an image.

. What is the blind spot in the eye?

Solution: The blind spot is the area on the retina where the optic nerve connects, lacking light-sensitive cells, resulting in no vision in that specific spot.

. Explain the working of a camera.

Solution: A camera works similar to the human eye. It focuses light through a lens onto a light-sensitive film or digital sensor, which captures the image.

. Define the term magnification.

Solution: Magnification is the ratio of the image size to the object size. It determines how much larger or smaller an image appears in comparison to the original object.

. What is the purpose of a telescope?

Solution: The purpose of a telescope is to gather and focus light from distant objects, making them appear closer and magnified.

. Explain the formation of a mirage.

Solution: A mirage is formed when light undergoes refraction due to temperature variations in the air, creating an optical illusion where an object appears displaced or inverted.

. How does a periscope work?

Solution: A periscope works through the use of multiple mirrors or prisms to reflect light, enabling one to see objects that are not in a direct line of sight.

. Describe the working of a microscope.

Solution: A microscope works by using lenses to magnify small objects. It has an objective lens that produces an enlarged real image, which is further magnified by an eyepiece lens.

. Why does a pencil appear bent when partially immersed in water?

Solution: A pencil appears bent when partially immersed in water due to the refraction of light as it transitions from water to air, causing the light rays to change direction.

. What is the cause of the twinkling of stars?

Solution: The twinkling of stars is caused by atmospheric refraction, where the light from stars is refracted by the Earth's atmosphere, resulting in the perceived twinkling effect.

. Explain the term optical density.

Solution: Optical density refers to how much a medium can slow down or bend light as it travels through it. It is measured by the refractive index.

. How does a lens form an image?

Solution: A lens forms an image by refracting and bending light rays that pass through it. For a convex lens, it forms a real or virtual image, and for a concave lens, it forms only a virtual image.

. What is the relationship between the angle of incidence and the angle of reflection?

Solution: The angle of incidence is always equal to the angle of reflection, according to the law of reflection.

. What is an antireflective coating?

Solution: An antireflective coating is a thin layer applied to the surface of an object to minimize the reflection of light, allowing more light to pass through, and reducing glare.

. What is the speed of light in a vacuum?

Solution: The speed of light in a vacuum is approximately 299,792,458 meters per second.

. How do concave and convex mirrors differ in terms of image formation? Solution: Concave mirrors can produce both real and virtual images, while convex mirrors only produce virtual images that are smaller and upright.

. What is the function of the iris in the human eye?

Solution: The iris controls the size of the pupil, regulating the amount of light entering the eye.

. Explain how a 3D movie works.

Solution: A 3D movie works by projecting two slightly offset images, one for each eye, which are then viewed through special glasses to create the perception of depth.

. How does the eye adjust focus to see objects at different distances?

Solution: The eye adjusts focus using the accommodation process, where the lens changes shape, becoming thicker or thinner, to focus light onto the retina for objects at various distances.

. Describe how a kaleidoscope works.

Solution: A kaleidoscope works by reflecting multiple mirrors inside a tube, creating a symmetrical pattern of multiple images of objects placed at one end of the tube.

Chapter 11 Human Eye and Colourful World

What is refraction?

Solution: Refraction is the bending of light when it passes from one medium to another medium.

Define the term 'apparent depth.'

Solution: Apparent depth is the depth of an object perceived by an observer, which may differ from its actual depth due to refraction of light.

How is a rainbow formed?

Solution: A rainbow is formed when sunlight enters the water droplets in the air, gets refracted, and then reflects off the droplet's inner surface, resulting in the separation of white light into its constituent colors.

Why do we see different colors in a rainbow?

Solution: Different colors of light have different wavelengths, and when white light is refracted and dispersed in a water droplet, each color component bends differently, resulting in the formation of a spectrum of colors.

Why is the sky blue during the daytime?

Solution: The sky appears blue during the daytime because of the scattering of sunlight by the tiny particles in the Earth's atmosphere.

Explain the process of scattering of light.

Solution: Scattering of light occurs when light interacts with various particles or molecules in the atmosphere, causing the light to change its direction.

Why does the sky sometimes appear red during sunrise or sunset?

Solution: During sunrise or sunset, the sunlight has to pass through a thicker layer of the atmosphere, which scatters shorter-wavelength colors like blue and green. As a result, the longer-wavelength red light appears more dominant, giving the sky a reddish hue.

What is the function of the lens in our eye?

Solution: The lens in our eye helps in focusing light onto the retina, which is important for forming clear images.

Name the part of the eye responsible for color vision.

Solution: The retina, specifically the cone cells present in the retina, are responsible for color vision.

. What is myopia?

Solution: Myopia, also known as nearsightedness, is an eye condition in which a person can see nearby objects clearly but has difficulty seeing distant objects.

. How does a concave lens help in correcting myopia?

Solution: A concave lens helps correct myopia by diverging the incoming light rays, thus compensating for the excess focusing power of the eye.

. Why can't people with color blindness distinguish certain colors?

Solution: Color blindness occurs due to the absence or malfunction of certain cone cells in the retina, resulting in the inability to distinguish specific colors.

. How does a convex lens help in correcting hypermetropia?

Solution: A convex lens helps correct hypermetropia by converging the incoming light rays, compensating for the focusing power of the eye.

. Explain the structure of the human eye.

Solution: The human eye consists of various parts such as the cornea, iris, pupil, lens, retina, optic nerve, and the ciliary muscles.

. Why do we experience a blind spot in our vision?

Solution: The blind spot in our vision is caused by the absence of light-sensitive cells, known as rods and cones, at the point where the optic nerve leaves the retina.

. What is astigmatism?

Solution: Astigmatism is an eye condition that occurs due to an irregularly shaped cornea, resulting in blurred or distorted vision at different distances.

. Name the primary colors of light.

Solution: The primary colors of light are red, green, and blue, commonly referred to as RGB.

. What are complementary colors?

Solution: Complementary colors are pairs of colors that, when combined, produce white light. The primary complementary color pairs are red-cyan, greenmagenta, and blue-yellow.

. Explain the concept of persistence of vision.

Solution: Persistence of vision refers to the optical illusion where an image appears to persist in our vision for a short duration even after its removal.

. What is chromatic aberration?

Solution: Chromatic aberration is an optical defect that causes different colors to focus at different distances behind a lens, resulting in blurred or fringed images.

. How does a camera lens focus light to form an image?

Solution: A camera lens uses the process of refraction to focus incoming light onto the camera's image sensor, allowing the formation of a clear image.

. What is total internal reflection?

Solution: Total internal reflection occurs when light traveling from a denser medium hits the interface with a less dense medium at an angle greater than the critical angle, causing the light to be completely reflected back.

. Explain the working of a human eye in a dark room.

Solution: In a dark room, the pupil of the eye dilates to allow more light to enter. The lens adjusts its shape to focus incoming light onto the retina, facilitating better vision in low-light conditions.

. What is the difference between a real image and a virtual image?

Solution: A real image can be projected onto a screen since the light rays physically converge at a specific point, while a virtual image cannot be projected and is formed by the apparent intersection of light rays.

. How does the eye adapt when we move from a dark room to a brightly lit area?

Solution: When we move from a dark room to a brightly lit area, the pupil of the eye constricts to allow less light to enter. This adjustment helps prevent excessive amounts of light from damaging the retina.

. Why does a pencil appear bent when partially submerged in water?

Solution: When a pencil is partially submerged in water, the light rays from the pencil undergo refraction at the water-air interface, causing them to change direction. This change in direction makes the pencil appear bent.

. What is the iris of the eye?

Solution: The iris is the colored portion of the eye that surrounds the pupil. It controls the size of the pupil and regulates the amount of light entering the eye.

. Why is the iris of some people dark while it appears light in others?

Solution: The color of the iris is determined by the amount and type of pigment present in it. People with higher melanin content in their iris tend to have darkercolored irises, while lower melanin content results in lighter-colored irises.

. What are the causes of nearsightedness or myopia?

Solution: Nearsightedness or myopia can be caused by a longer-than-normal eyeball, an excessively curved cornea, or a combination of both.

. Which cells in the retina are responsible for black and white vision?

Solution: The rod cells present in the retina are responsible for black and white vision.

. How is the focal length of a lens related to its power?

Solution: The power of a lens is inversely proportional to its focal length. A lens with a shorter focal length has greater power, while a lens with a longer focal length has lower power.

. What happens to the speed of light when it enters a denser medium?

Solution: The speed of light decreases when it enters a denser medium due to frequent interactions with particles, resulting in a change in direction.

. Explain the difference between converging and diverging lenses.

Solution: Converging lenses are thicker at the center than at the edges and converge light rays towards a focal point. Diverging lenses are thinner at the center than at the edges and diverge light rays away from a focal point.

. How does the human eye adjust its focal length to focus on objects at different distances?

Solution: The human eye adjusts its focal length by changing the shape of the lens through the action of the ciliary muscles. Thicker lens shape allows for focusing on nearby objects, while a flatter lens shape allows for focusing on distant objects.

. Why do we see a distorted image when looking through a glass of water?

Solution: When looking through a glass of water, the light rays undergo refraction as they pass through the water-air interface. This refraction causes the image to appear distorted or displaced.

. What is the role of the cornea in the eye?

Solution: The cornea is the transparent outer covering of the eye. It helps in focusing incoming light and provides most of the eye's focusing power.

. What is the function of the optic nerve?

Solution: The optic nerve carries electrical signals from the retina to the brain, allowing the brain to process visual information.

. How does the brain interpret the signal received from the retina to form an image?

Solution: The brain receives electrical signals from the optic nerve and processes them by combining various sensory inputs, allowing us to perceive and interpret the visual information as an image.

. What is the rainbow angle?

Solution: The rainbow angle is the angle between the incident sunlight and the line connecting the observer's eye to the center of the rainbow.

. Can a rainbow be observed during noon?

Solution: A rainbow is usually observed when sunlight is refracted, reflected, and dispersed by water droplets in the air. During noon, when the sun is at its highest, the angle between the sunlight and observer's eye is not favorable for observing a rainbow.

. What causes a secondary rainbow to form?

Solution: A secondary rainbow is formed due to a double reflection of sunlight inside the raindrops, resulting in an inverted sequence of colors compared to a primary rainbow.

. Why are rainbows always circular in shape?

Solution: Rainbows appear circular because each individual raindrop disperses and reflects light in all directions, creating a circular pattern around the anti-solar point.

. Do all raindrops contribute to the formation of a rainbow?

Solution: No, only the raindrops that are between 1 and 2 millimeters in diameter contribute to the formation of a rainbow. Larger or smaller droplets do not produce a noticeable rainbow.

. How does the width of a rainbow vary?

Solution: The width of a rainbow depends on the size of the raindrops and the observer's position. On average, a rainbow appears about 1 degree wide.

. Can a rainbow be observed from an airplane?

Solution: Yes, a rainbow can be observed from an airplane if the sunlight and raindrops are in the right position relative to the observer.

. What is the phenomenon of supernumerary rainbows?

Solution: Supernumerary rainbows are additional, fainter rainbows that appear on the inner side of the primary rainbow. They are caused by the interference of light waves within the water droplets.

. Why are the colors of a rainbow always in the same order?

Solution: The colors in a rainbow (red, orange, yellow, green, blue, indigo, and violet) always appear in the same order because they correspond to the different wavelengths of visible light.

. What is the condition for observing a "moonbow"?

Solution: A moonbow, which is a rainbow caused by the reflection and refraction of moonlight instead of sunlight, can be observed when the moon is nearly full, low on the horizon, and the sky is dark.

. How does the phenomenon "glory" occur?

Solution: A glory is a multicolored ring of light that forms when sunlight is scattered backwards by small water droplets or cloud particles in the atmosphere.

. Why does a rainbow disappear when we move towards it?

Solution: A rainbow appears at a specific angle between the sunlight, raindrops, and the observer's eye. When you move towards the rainbow, the angle no longer remains constant, and the rainbow seems to shift, eventually disappearing as you reach the position where the rainbow would have been.

Chapter 12 Electricity

What is electricity? - Electricity is the flow of electric charge through a conductor.

Define electric current.

- Electric current is the rate of flow of electric charge.

What is the SI unit of electric current?

- The SI unit of electric current is ampere (A).

State Ohm's law.

- Ohm's law states that the current flowing through a conductor is directly proportional to the voltage across it, and inversely proportional to its resistance.

Explain the concept of voltage.

- Voltage is the electrical potential difference between two points, which causes the electric current to flow.

Define resistance.

- Resistance is the property of a conductor that opposes the flow of electric current.

What is the SI unit of resistance?

- The SI unit of resistance is ohm (?).

Describe the role of a conductor in an electric circuit.

- A conductor allows the flow of electric current through it easily due to the availability of free electrons.

What is an insulator?

- An insulator is a material that inhibits or prevents the flow of electric current through it.

. Explain the difference between series and parallel circuits.

- Series Circuit: In a series circuit, components are connected in a single loop, and the same current flows through each component. - Parallel Circuit: In a parallel circuit, components are connected across multiple paths, and the voltage across each component remains the same.

. Define electric power.

- Electric power is the rate at which electric energy is consumed or produced.

. What is the SI unit of electric power?

- The SI unit of electric power is watt (W).

. How is electric power related to current and voltage?

- Electric power is the product of current and voltage, i.e., P = VI.

. State the difference between an electric fuse and a circuit breaker.

- An electric fuse consists of a small wire that melts when excessive current flows through it, thus breaking the circuit. - A circuit breaker is an automatic switch that opens the circuit when excessive current flows, preventing damage to the circuit.

. Explain the working principle of an electric bulb.

- An electric bulb converts electrical energy into light and heat energy. When current flows through the filament, it gets heated and emits light.

. Define electric cell.

- An electric cell is a device that converts chemical energy into electrical energy.

. State the difference between a primary cell and a secondary cell.

- A primary cell cannot be recharged, while a secondary cell can be recharged.

. What is the potential difference of a cell?

- The potential difference of a cell is the voltage it can provide.

. What is electromotive force (EMF)?

- Electromotive force is the potential difference provided by a cell when no current is flowing through it.

. Explain the concept of short circuit.

- A short circuit occurs when a low-resistance path is created unintentionally in an electric circuit, resulting in a very high current flow.

. Define electric earthing.

- Electric earthing is the process of connecting electrical devices or circuits to the earth to prevent electric shocks and ensure safety.

. What is a circuit diagram?

- A circuit diagram is a graphical representation of an electric circuit that uses symbols to show the components and connections.

. Explain the working of an electric bell.

- An electric bell consists of an electromagnet that gets energized when current flows through it, attracting an iron armature and producing a ringing sound.

. State the difference between a conductor and a semiconductor.

- A conductor readily allows the flow of electric current, while a semiconductor has intermediate conductive properties.

. What is a diode?

- A diode is an electronic component that allows current to flow in only one direction and blocks it in the other direction.

. Define electric discharge.

- Electric discharge is the release of stored electrical energy, often in the form of a spark or flash.

. What is an electric circuit?

- An electric circuit is a closed loop or path through which electric current flows.

. Describe the concept of potential difference.

- Potential difference is the measure of energy transferred from one point to another per unit charge.

. Explain the concept of electric shock.

- Electric shock refers to the physiological reaction produced by the flow of electric current through a human body, causing injury or harm.

. What is the role of an electric switch in a circuit?

- An electric switch controls the flow of electric current in a circuit by either completing or breaking the circuit.

. Define the term "resistivity."

- Resistivity is the intrinsic property of a material to resist the flow of electric current.

. State the factors affecting the resistance of a conductor.

- Resistance depends on the length, cross-sectional area, and resistivity of the conductor material.

. How can you increase the resistance of a conductor?

- The resistance of a conductor can be increased by increasing its length, decreasing its cross-sectional area, or using materials with high resistivity.

. Explain the working principle of an electric motor.

- An electric motor converts electrical energy into mechanical energy. It works on the principle of the magnetic effect of electric current.

. What is the role of a transformer in an electric supply system?

- A transformer is used to step up or step down the voltage in an electric supply system for efficient transmission and distribution of electrical energy.

. Define the terms "AC" and "DC."

- AC (alternating current) periodically changes its direction, whereas DC (direct current) flows continuously in one direction.

. Explain the concept of electric field.

- Electric field is a region around an electric charge or a group of charges where the electric force can be exerted on other charges.

. State the difference between a series and a parallel combination of resistors.

- Series Combination: In a series combination of resistors, the total resistance is equal to the sum of individual resistances. - Parallel Combination: In a parallel combination of resistors, the reciprocal of total resistance is equal to the sum of reciprocals of individual resistances.

. What are the health hazards of electric current?

- Electric current can cause burns, muscular contractions, heart problems, and even death if it flows through a human body.

. Explain the concept of electric potential.

- Electric potential at a point in an electric field is the work done per unit charge to bring a positive test charge from infinity to that point.

. What is the role of a voltmeter in an electric circuit?

- A voltmeter is used to measure the potential difference or voltage across a component or between two points in an electric circuit.

. Define superconductivity.

- Superconductivity is the property of certain materials to exhibit zero electrical resistance at or below a critical temperature.

. Explain the working principle of an electric generator.

- An electric generator converts mechanical energy into electrical energy by electromagnetic induction.

. State the difference between a battery and a cell.

- A battery is a group of cells connected to provide a higher potential difference or voltage than a single cell.

. What is the role of a resistor in an electric circuit?

- A resistor is used to control the amount of current flowing through a circuit and dissipate excess energy in the form of heat.

. Explain the concept of electrical conductivity.

- Electrical conductivity refers to how easily a material allows the flow of electric current when a potential difference is applied.

. Define the term "electrolyte."

- An electrolyte is a substance that conducts electricity when dissolved in a solvent or when in a molten state.

. State the difference between a closed circuit and an open circuit.

- Closed Circuit: In a closed circuit, there is a complete path for the flow of electric current. - Open Circuit: In an open circuit, there is a break in the path, and no current flows.

. What is the role of a resistor in an LED circuit?

- A resistor is added in series with an LED to limit the current flowing through it and protect it from damage.

. Explain the concept of electrical energy.

- Electrical energy is the ability to do work by moving electric charges. It is the product of power and time.

Chapter 13 Magnetic Effects of Electric Current

What is a magnetic field?

Solution: A magnetic field is the region around a magnet or a current-carrying conductor where its magnetic influence can be observed.

State the right-hand thumb rule.

Solution: The right-hand thumb rule is used to determine the direction of magnetic field lines around a current-carrying conductor. If the thumb points in the direction of current, the fingers indicate the direction of the magnetic field.

What is the unit of magnetic field strength?

Solution: The unit of magnetic field strength is Tesla (T).

Define magnetic field lines.

Solution: Magnetic field lines represent the direction and strength of a magnetic field. They are imaginary lines that run from the north pole of a magnet to its south pole.

What is an electromagnet?

Solution: An electromagnet is a temporary magnet that is created by passing an electric current through a coil of wire wound around a soft iron core.

State the factors affecting the strength of an electromagnet.

Solution: The factors affecting the strength of an electromagnet are the number of turns in the coil, the current flowing through the coil, and the core material.

What is the principle of an electric motor?

Solution: The principle of an electric motor is based on the interaction between a magnetic field and an electric current, which results in the rotation of a coil and shaft.

Differentiate between direct current (DC) and alternating current (AC).

Solution: Direct current flows continuously in one direction, while alternating current periodically changes its direction.

State the rule to determine the direction of force acting on a current-carrying conductor placed in a magnetic field.

Solution: Fleming's left-hand rule is used to determine the direction of force acting on a current-carrying conductor placed in a magnetic field. The thumb, forefinger, and middle finger represent the direction of the magnetic field, current, and force, respectively.

. What is electromagnetic induction?

Solution: Electromagnetic induction is the process of generating an electric current in a conductor by varying the magnetic field linked with it.

. Define the term 'magnetic field intensity.'

Solution: Magnetic field intensity is a measure of the strength of a magnetic field at a given point. It is directly proportional to the magnetic field force at that point.

. Explain the working principle of an AC generator.

Solution: An AC generator works on the principle of electromagnetic induction. It consists of a coil that rotates in a magnetic field, which induces an alternating current.

. How can the strength of an electromagnet be increased?

Solution: The strength of an electromagnet can be increased by increasing the number of turns in the coil, increasing the current flow, and using a magnetic core material with high magnetic permeability.

. State two uses of electromagnets.

Solution: Electromagnets are used in electric bells, cranes, magnetic locks, and in various industrial applications where temporary and controlled magnetic fields are required.

. What is a solenoid?

Solution: A solenoid is a long coil of insulated wire, which produces a strong and uniform magnetic field when an electric current flows through it.

. Differentiate between a permanent magnet and an electromagnet.

Solution: A permanent magnet produces its own magnetic field without any external influence, while an electromagnet requires a current flow through the coil to generate a magnetic field.

. Explain the working of a doorbell using an electromagnet.

Solution: When the doorbell button is pressed, an electric current flows through the coil of an electromagnet, creating a magnetic field that attracts an iron striker, producing a sound.

. What are magnetic field lines? How do they represent the strength of a magnetic field?

Solution: Magnetic field lines are imaginary lines that represent the direction and strength of a magnetic field. The density of field lines at a point indicates the strength of the magnetic field: the denser the lines, the stronger the field.

. Define magnetic flux.

Solution: Magnetic flux is a measure of the total magnetic field passing through a given area perpendicular to the field.

. How can the direction of current in a wire affect the strength of its magnetic field?

Solution: The direction of current flowing in a wire determines the direction of its magnetic field. If the current direction is reversed, the magnetic field associated with it also reverses.

. State Faraday's law of electromagnetic induction.

Solution: Faraday's law of electromagnetic induction states that the induced electromotive force (EMF) in a circuit is directly proportional to the rate of change of magnetic field linked with the circuit.

. What is the function of a commutator in a DC motor?

Solution: The commutator in a DC motor reverses the direction of current in the coil, ensuring a continuous rotation of the motor by reversing the direction of the magnetic field.

. How does the magnetic field produced by an electromagnet differ from that of a permanent magnet?

Solution: The magnetic field produced by an electromagnet can be controlled by varying the electric current, whereas the magnetic field of a permanent magnet is fixed.

. Name the factors on which the magnitude of the magnetic force experienced by a current-carrying conductor in a magnetic field depends.

Solution: The magnitude of the magnetic force experienced by a current-carrying conductor depends on the strength of the magnetic field, the current flowing through the conductor, and the length of the conductor.

. Describe the working of a galvanometer.

Solution: A galvanometer is a device that measures small electric currents. It works on the principle of the magnetic effect of electric current, where a currentcarrying coil experiences a torque in a magnetic field, leading to deflection.

. What is back EMF in an electric motor?

Solution: Back EMF (electromotive force) is the voltage produced in the coil of an electric motor due to the rotation of the coil in a magnetic field. It opposes the applied voltage and reduces the net voltage across the motor.

. Explain the concept of a step-up transformer.

Solution: A step-up transformer is a device that increases the voltage of an alternating current (AC). It has more turns in the secondary coil than in the primary coil, resulting in higher output voltage.

. State Ampere's circuital law.

Solution: Ampere's circuital law states that the magnetic field produced by a current-carrying conductor is directly proportional to the current passing through it and inversely proportional to the distance from the conductor.

. What is the difference between a step-up transformer and a step-down transformer?

Solution: A step-up transformer increases the voltage and decreases the current, while a step-down transformer decreases the voltage and increases the current.

. How does the strength of the magnetic field inside a solenoid depend on the current passing through it?

Solution: The strength of the magnetic field inside a solenoid is directly proportional to the current passing through it. As the current increases, the magnetic field strength also increases.

. What is the importance of the soft iron core in an electromagnet?

Solution: The soft iron core in an electromagnet enhances the strength of the magnetic field produced by the coil as it easily magnetizes and demagnetizes, increasing the overall magnetic effect.

. Explain the principle of a transformer.

Solution: The principle of a transformer is based on Faraday's law of electromagnetic induction. It consists of two coils, primary and secondary, wound around an iron core. Alternating current in the primary coil induces a varying magnetic field, which in turn induces current in the secondary coil.

. Define magnetic declination.

Solution: Magnetic declination is the angle between the geographic north and the magnetic north at a particular location.

. How can the direction of a magnetic field be determined using a compass?

Solution: The needle of a compass aligns in the north-south direction due to the Earth's magnetic field. By observing the direction of the compass needle, the direction of the magnetic field can be determined.

. State two differences between magnetic field lines and electric field lines.

Solution: Magnetic field lines form closed loops, while electric field lines start from positive charges and end at negative charges. Magnetic field lines do not have a starting or ending point.

. What are the applications of magnetic effect of electric current in everyday life?

Solution: The applications of the magnetic effect of electric current include transformers, electric motors, doorbells, loudspeakers, electric generators, and magnetic storage devices like hard disks.

. Explain the construction and working of an electric generator.

Solution: An electric generator consists of a coil of wire wrapped around an armature, which rotates in a magnetic field. As the coil rotates, the magnetic field induces an alternating current in the coil.

. What is a step-down transformer? Where is it commonly used?

Solution: A step-down transformer is a device that reduces the voltage of an alternating current (AC). It has fewer turns in the secondary coil than in the primary coil. It is commonly used to step down the voltage for domestic and commercial purposes.

. Explain the principle of a loudspeaker.

Solution: A loudspeaker works on the principle of the interaction between a magnetic field and an electric current. When an electric current passes through a coil in the loudspeaker, it creates a varying magnetic field that interacts with a permanent magnet, causing the speaker cone to vibrate and produce sound.

. Define eddy currents. How can they be minimized?

Solution: Eddy currents are small and localized currents induced in a conductor due to the changing magnetic field. They can be minimized by using a laminated (insulated) core for the conductor.

. State the factors affecting the strength of an electromagnet created by a solenoid.

Solution: The factors affecting the strength of an electromagnet created by a solenoid are the number of turns in the coil, the current passing through the coil, and the core material used.

. What is a DC motor? Explain its working.

Solution: A DC motor is a device that converts electrical energy into mechanical energy using the principle of the magnetic effect of electric current. It consists of a coil placed in a magnetic field, which experiences a torque when current flows through it. This torque leads to rotation.

. Describe the construction and working of a transformer.

Solution: A transformer consists of a soft iron core surrounded by two coils, primary and secondary coils. When an alternating current passes through the primary coil, it produces a varying magnetic field that induces current in the secondary coil through electromagnetic induction. 44. What are magnetic poles? How many types of magnetic poles are there? Solution: Magnetic poles are the regions of a magnet where the magnetic field is concentrated the most. There are two types of magnetic poles: the north pole and the south pole.

. How can the strength of the magnetic field inside a solenoid be increased?

Solution: The strength of the magnetic field inside a solenoid can be increased by increasing the number of turns in the coil and increasing the current passing through the solenoid.

. Explain how the phenomenon of electromagnetic induction is utilized in a generator.

Solution: In a generator, the phenomenon of electromagnetic induction is utilized to convert mechanical energy into electrical energy. When a coil rotates in a magnetic field, the magnetic flux linked with the coil changes, inducing an electromotive force (EMF) or voltage.

. What will happen to the direction of a current-carrying wire if it is placed parallel to a magnetic field?

Solution: If a current-carrying wire is placed parallel to a magnetic field, it will experience no force and will continue to flow in the same direction.

. An electric motor and a generator work on similar principles. Explain.

Solution: An electric motor and a generator both work on the principles of electromagnetic induction and the magnetic effect of electric current. In an electric motor, electrical energy is converted into mechanical energy, while in a generator, mechanical energy is converted into electrical energy.

. What is magnetic susceptibility? How does it vary for diamagnetic and ferromagnetic substances?

Solution: Magnetic susceptibility is a measure of the ability of a substance to become magnetized in the presence of a magnetic field. Diamagnetic substances have negative magnetic susceptibility, meaning they slightly repel magnetic fields. Ferromagnetic substances have a high positive magnetic susceptibility, as they can be strongly magnetized in the presence of a magnetic field.

. What is the function of a split ring commutator in a DC motor?

Solution: A split ring commutator in a DC motor reverses the direction of current in the coil every half rotation, ensuring the coil continues to rotate in the same direction. It converts the alternating current induced in the coil into direct current.

Chapter 14 Sources of Energy

Q: What are the different sources of energy?

A: The different sources of energy include fossil fuels, nuclear energy, renewable energy sources like solar, wind, hydroelectric power, biomass, etc.

Q: What are fossil fuels?

A: Fossil fuels are formed from the remains of plants and animals that lived millions of years ago. Coal, petroleum, and natural gas are examples of fossil fuels.

Q: What is the main drawback of using fossil fuels?

A: The main drawback of using fossil fuels is that they contribute to air pollution and the greenhouse effect, leading to climate change.

Q: How is electricity generated from coal? A: Coal is burned in power plants to produce steam, which turns a turbine to generate electricity.

Q: What is the renewable source of energy?

A: Renewable sources of energy are those that are naturally replenished, like solar energy, wind energy, hydroelectric power, and biomass.

Q: How is electricity generated from solar energy?

A: Solar cells or photovoltaic cells convert sunlight directly into electricity.

Q: What is the largest source of renewable energy in the world?

A: Solar energy is the largest source of renewable energy globally.

Q: How is wind energy harnessed to generate electricity?

A: Wind turbines convert the kinetic energy of the wind into mechanical energy, which is then converted into electricity.

Q: What is hydroelectric power?

A: Hydroelectric power is generated by utilizing the kinetic energy of flowing or falling water to turn turbines and generate electricity.

Q: What is tidal energy?

A: Tidal energy is obtained from the rise and fall of tides. Tidal barrages or tidal turbines are used to convert tidal energy into electricity.

Q: What is geothermal energy?

A: Geothermal energy is the heat energy obtained from the Earth's interior. It is utilized for generating electricity and heating purposes.

Q: How is biomass energy obtained?

A: Biomass energy is obtained from organic matter such as wood, crop residues, and animal waste. It can be burned directly or converted into biogas or biofuels.

Q: How is nuclear energy generated?

A: Nuclear energy is generated by the process of nuclear fission in which the nucleus of an atom is split and releases a tremendous amount of energy.

Q: What are the advantages of nuclear energy?

A: The advantages of nuclear energy include high energy efficiency, low greenhouse gas emissions, and a large amount of energy generation from small amounts of fuel.

Q: What are the disadvantages of nuclear energy?

A: The main disadvantages of nuclear energy are the risk of accidents, high cost, generation of long-lasting radioactive waste, and potential for nuclear weapons proliferation.

Q: What are the different components of a solar cooker?

A: A solar cooker consists of a reflector, a cooking pot, and a glass cover to trap solar heat.

Q: What is a solar water heater?

A: A solar water heater uses solar energy to heat water for domestic or industrial purposes.

Q: What is the working principle of a hydroelectric power plant?

A: A hydroelectric power plant works by using the potential energy of the stored water in a dam. The water flows down through turbines, which in turn generate electricity.

Q: How is wind energy beneficial for remote areas?

A: Wind energy can be harnessed in remote areas to generate electricity, providing an independent and clean source of power for those regions.

Q: What is the role of a turbine in energy conversion?

A: Turbines convert the mechanical energy from various sources, such as wind, water, or steam, into electricity.

Q: Which fossil fuel is most commonly used in thermal power plants?

A: Coal is the most commonly used fossil fuel in thermal power plants.

Q: What is the process of natural gas formation?

A: Natural gas is formed from decomposed plant and animal matter buried deep underground over millions of years.

Q: What is the impact of burning fossil fuels on the environment?

A: Burning fossil fuels releases pollutants into the air, causing air pollution, global warming, and acid rain.

Q: How does the burning of fossil fuels contribute to climate change?

A: The burning of fossil fuels releases greenhouse gases such as carbon dioxide, which trap heat in the Earth's atmosphere and lead to global warming.

Q: How can we conserve energy at home?

A: We can conserve energy at home by switching off lights and appliances when not in use, using energy-efficient devices, insulating our homes, and relying on natural lighting and ventilation.

Q: What is the importance of energy conservation?

A: Energy conservation is essential to reduce the depletion of non-renewable energy resources, save money, and decrease environmental pollution.

Q: How can solar energy be harnessed on a large scale?

A: Large-scale solar energy can be harnessed through solar power plants or solar farms, where multiple solar panels are installed to generate electricity.

Q: What is the major drawback of solar energy?

A: The major drawback of solar energy is its intermittent nature, as it depends on the availability of sunlight.

Q: How does a biomass power plant function?

A: In a biomass power plant, organic matter like wood or agricultural waste is burned to produce steam, which then drives a turbine to generate electricity.

Q: What is the concept of a nuclear reactor?

A: A nuclear reactor is a facility that controls and sustains a nuclear chain reaction to release a large amount of heat energy.

Q: How can we ensure the safe disposal of nuclear waste?

A: Nuclear waste can be safely disposed of by burying it deep underground in containers designed to prevent leakage and contamination of the environment.

Q: How is hydroelectricity classified under renewable energy?

A: Hydroelectricity is classified as renewable energy because it relies on the continuous replenishment of water through the hydrological cycle.

Q: What is the difference between a renewable and non-renewable energy source?

A: Renewable energy sources can be naturally replenished, while non-renewable energy sources exist in limited quantities and are depleted over time.

Q: Why is wind energy considered a clean source of power?

A: Wind energy is considered clean because it does not release harmful pollutants or greenhouse gases during its operation.

Q: What are the factors determining the location of wind farms?

A: The factors determining the location of wind farms include wind speed, availability of land, transmission lines, and environmental impact assessments.

Q: What is the role of a control rod in a nuclear reactor?

A: Control rods absorb excess neutrons to control the rate of the nuclear reaction in a nuclear reactor.

Q: Why is energy conservation important in industries?

A: Energy conservation is important in industries to reduce costs, increase efficiency, and minimize the environmental impact of energy-intensive processes.

Q: How does the greenhouse effect occur?

A: The greenhouse effect occurs when certain gases in the atmosphere trap heat from the sun, leading to an increase in global temperatures.

Q: How can we reduce our dependence on non-renewable energy sources?

A: We can reduce our dependence on non-renewable energy sources by promoting the use of renewable energy technologies, energy conservation, and adopting sustainable practices.

Q: What are the environmental benefits of using renewable energy sources?

A: Renewable energy sources help reduce air pollution, decrease greenhouse gas emissions, and conserve natural resources.

Q: How does the rotation of wind turbines generate electricity?

A: The rotation of wind turbines turns a generator, which converts the mechanical energy of the wind into electrical energy.

Q: What is the efficiency of a typical thermal power plant?

A: The efficiency of a typical thermal power plant is around 35-40%.

Q: What causes the movement of the tides? A: The gravitational pull of the moon and the sun causes the movement of tides.

Q: What are the advantages of using fossil fuels?

A: Fossil fuels are energy-dense, easily transportable, and have a well-established infrastructure for extraction, distribution, and usage.

Q: What is the full form of CNG?

A: CNG stands for Compressed Natural Gas.

Q: What type of renewable energy is obtained from organic waste materials?

A: Biogas, a mixture of methane and carbon dioxide, is obtained from organic waste materials and can be used as a renewable energy source.

Q: What is the working principle of a solar panel?

A: Solar panels consist of photovoltaic cells that convert sunlight into direct current (DC) electricity by the photovoltaic effect.

Q: What role does water play in a nuclear reactor?

A: Water in a nuclear reactor serves as both a coolant and a moderator to regulate the reaction and carry away heat.

Q: What are the primary uses of geothermal energy?

A: Geothermal energy is primarily used for electricity generation, heating systems, and directly heating water in geothermal hot springs.

Q: How can we make our homes more energy efficient?

A: We can make our homes more energy efficient by insulating walls and roofs, using energy-efficient appliances, sealing air leaks, and utilizing natural lighting and ventilation.

Chapter 15 Our Environment

Q: What is an environment?

A: The environment refers to the surroundings in which organisms live, including both living and non-living components.

Q: Define ecosystem.

A: An ecosystem is a community of organisms interacting with each other and their physical environment.

Q: What are the components of an ecosystem?

A: The components of an ecosystem include biotic (living) factors like plants, animals, and microorganisms, as well as abiotic (non-living) factors like air, water, soil, and sunlight.

Q: Explain the concept of biodiversity.

A: Biodiversity refers to the variety of living organisms present in a particular ecosystem or on the entire planet.

Q: Why is biodiversity important?

A: Biodiversity is important as it contributes to the stability, productivity, and resilience of ecosystems. It also provides various ecosystem services and supports the life on Earth.

Q: What are producers in an ecosystem?

A: Producers, such as plants and some bacteria, are organisms that can convert sunlight into food through photosynthesis.

Q: Name the different types of consumers in an ecosystem.

A: Consumers can be classified into different types: herbivores (plant eaters), carnivores (meat eaters), omnivores (both plant and meat eaters), and decomposers (break down dead organic matter).

Q: What is the role of decomposers in an ecosystem?

A: Decomposers play a crucial role in the ecosystem by breaking down dead organisms and organic waste, returning nutrients to the soil.

Q: What is the ozone layer and why is it important?

A: The ozone layer is a protective layer of ozone gas in the Earth's atmosphere. It absorbs most of the Sun's ultraviolet (UV) radiation, which is harmful to living organisms.

Q: What is global warming?

A: Global warming refers to the increase in Earth's average temperature due to greenhouse gas emissions, primarily carbon dioxide, trapping heat in the Earth's atmosphere.

Q: How does deforestation impact the environment?

A: Deforestation leads to the loss of forests, disrupting habitats, reducing biodiversity, increasing soil erosion, and contributing to climate change.

Q: Explain the concept of sustainable development.

A: Sustainable development refers to meeting the present needs without compromising the ability of future generations to meet their own needs.

Q: What are renewable resources?

A: Renewable resources are natural resources that can be regenerated or replenished over time, such as solar energy, wind energy, and water.

Q: Name some non-renewable resources.

A: Non-renewable resources are those that cannot be easily replenished, like fossil fuels (coal, oil, natural gas) and minerals.

Q: What are the causes of air pollution?

A: Air pollution can be caused by the release of harmful gases, smoke, dust, and pollutants from industries, vehicles, burning of fossil fuels, and human activities.

Q: Define water pollution.

A: Water pollution refers to the contamination of water bodies like rivers, lakes, and oceans due to the discharge of pollutants and wastes.

Q: How does noise pollution affect human health?

A: Noise pollution can lead to various health issues like stress, hearing loss, sleep disturbances, and impaired concentration.

Q: Name some measures to conserve water.

A: Some measures to conserve water include fixing leaky taps, using water-saving appliances, reducing wastage during domestic usage, and promoting rainwater harvesting.

Q: What is meant by the 3 R's in waste management?

A: The 3 R's, which stand for Reduce, Reuse, and Recycle, are principles aimed at minimizing waste by reducing consumption, reusing products, and recycling materials.

Q: How does the use of pesticides impact the environment?

A: The excessive use of pesticides can lead to the contamination of soil, water, and air, harming non-target organisms and disrupting ecosystems.

Q: Explain the concept of sustainable agriculture.

A: Sustainable agriculture focuses on producing food in an environmentally friendly and socially responsible manner, minimizing the use of harmful chemicals and preserving natural resources.

Q: What are the greenhouse gases?

A: Greenhouse gases are gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) that trap heat in the Earth's atmosphere, contributing to global warming.

Q: How can we reduce the production of greenhouse gases?

A: We can reduce greenhouse gas emissions by using renewable energy sources, conserving energy, promoting energy-efficient technologies, and adopting sustainable transportation methods.

Q: Define the term 'acid rain.'

A: Acid rain refers to rainwater or any other form of precipitation that is acidic due to the presence of air pollutants like sulfur dioxide and nitrogen oxides.

Q: How does acid rain affect the environment?

A: Acid rain can damage forests, soil, plants, and aquatic ecosystems, as well as corrode buildings and structures.

Q: What is the role of the government in environmental conservation?

A: The government plays a crucial role in implementing policies, regulations, and laws to protect the environment, promote sustainable practices, and monitor environmental issues.

Q: What is a food chain?

A: A food chain represents the transfer of energy and nutrients from one organism to another in a linear sequence.

Q: Differentiate between food chain and food web.

A: A food chain represents a single pathway of energy flow, while a food web is a complex network of interconnected food chains in an ecosystem.

Q: Define the term 'biomagnification.'

A: Biomagnification refers to the increase in the concentration of certain toxic substances as they pass through trophic levels in a food chain.

Q: What is an ecological pyramid?

A: An ecological pyramid is a graphical representation that shows the relative quantities of energy or number of organisms at different trophic levels in an ecosystem.

Q: What is an ozone hole?

A: An ozone hole refers to the thinning of the ozone layer, primarily in the polar regions, caused by the release of chlorofluorocarbons (CFCs) and similar substances.

Q: How does population growth impact the environment?

A: Population growth puts pressure on resources, leads to habitat destruction, increases waste generation, and contributes to pollution and environmental degradation.

Q: What is the role of wetlands in the environment?

A: Wetlands play a crucial role in flood control, water purification, providing habitats for various species, and acting as a buffer against climate change impacts.

Q: Explain the concept of an 'endangered species.'

A: An endangered species is a species that is facing a high risk of extinction in the near future due to various factors like habitat loss, poaching, or climate change.

Q: How can we conserve energy in our daily lives?

A: We can conserve energy by adopting practices like switching off lights when not needed, using energy-efficient appliances, reducing air conditioning usage, and maximizing natural light.

Q: What are the harmful effects of plastic on the environment?

A: Plastic pollution leads to the contamination of land, water bodies, and ecosystems and poses a threat to wildlife through ingestion or entanglement in plastic waste.

Q: What is soil erosion, and how can it be controlled?

A: Soil erosion is the process by which topsoil is removed or displaced by wind, water, or other factors. It can be controlled by adopting measures like contour plowing, terracing, and afforestation.

Q: Name some sustainable transportation methods.

A: Sustainable transportation methods include using public transport, cycling, carpooling, and promoting the use of electric vehicles.

Q: What is the greenhouse effect?

A: The greenhouse effect is a natural phenomenon where certain gases in the Earth's atmosphere trap heat, maintaining a suitable temperature for life.

Q: How can we reduce air pollution from vehicles?

A: We can reduce air pollution from vehicles by using cleaner fuel options like compressed natural gas (CNG) or electric vehicles, maintaining proper vehicle maintenance, and promoting public transportation.

Q: What is the significance of the 'Swachh Bharat Abhiyan' campaign?

A: The Swachh Bharat Abhiyan campaign aims to promote cleanliness, hygiene, and proper waste management practices in India, contributing to a healthier environment.

Q: How does habitat destruction affect wildlife?

A: Habitat destruction leads to the loss of suitable living spaces, causing a decline in wildlife populations, loss of biodiversity, and disruption of ecological balance.

Q: Define the term 'pollutant.'

A: A pollutant is any substance or agent that has negative effects on the environment, causing pollution.

Q: Explain the concept of 'renewable energy sources.'

A: Renewable energy sources are those that are naturally replenished and have a minimal impact on the environment, including solar, wind, hydro, and geothermal energy.

Q: What is the role of wetlands in climate change mitigation?

A: Wetlands can act as carbon sinks, trapping and storing carbon dioxide, thus helping in mitigating climate change by reducing greenhouse gas levels.

Q: How can individuals contribute to environmental conservation?

A: Individuals can contribute to environmental conservation by practicing waste reduction and recycling, conserving energy and water, planting trees, and raising awareness about environmental issues.

Q: Define the term 'symbiosis.'

A: Symbiosis refers to a close and often long-term interaction between different species, which can be mutually beneficial (mutualism), harmful (parasitism), or one-sided (commensalism).

Q: What is biological magnification?

A: Biological magnification, also known as bioaccumulation, refers to the accumulation of certain harmful substances in the tissues of organisms as they move up the food chain.

Q: How can noise pollution be minimized?

A: Noise pollution can be minimized by using sound barriers, implementing regulations for noise control, and creating noise-buffer zones.

Q: Why is it important to conserve water?

A: It is important to conserve water as it is a finite resource essential for all life forms, and wastage can lead to water scarcity, ecological imbalance, and various environmental issues.

Chapter 16 Management of Natural Resources

Q: What is meant by natural resources?

A: Natural resources are the substances or components of the environment that have economic and ecological value.

Q: Give three examples of natural resources.

A: Examples include air, water, forests, minerals, fossil fuels, and wildlife.

Q: Define sustainable management of natural resources.

A: Sustainable management involves utilizing natural resources in a way that meets current needs without compromising future generations.

Q: Why is water considered a precious natural resource?

A: Water is essential for all living organisms and is necessary for various activities like drinking, irrigation, and industrial processes.

Q: What are the causes of water scarcity?

A: The main causes include overuse, pollution, inadequate infrastructure, climate change, and inefficient water management practices.

Q: How can water be conserved at a domestic level?

A: Water can be conserved by fixing leaky faucets, taking shorter showers, using water-saving appliances, and harvesting rainwater.

Q: Define the term 'water harvesting.'

A: Water harvesting refers to the collection and storage of rainwater for various purposes like irrigation, drinking, and recharge of groundwater.

Q: What is the importance of afforestation?

A: Afforestation helps in preventing soil erosion, maintaining the water table, providing habitat for wildlife, and reducing carbon dioxide levels.

Q: How does deforestation affect the environment?

A: Deforestation leads to soil erosion, loss of biodiversity, climate change, disturbance in the water cycle, and floods.

Q: What are the advantages of using renewable sources of energy?

A: Renewable sources like solar, wind, and hydroelectric power are clean, abundant, and do not deplete natural resources or emit harmful pollutants.

Q: Give an example of a renewable source of energy that is derived from biomass.

A: Biofuel, which is derived from organic materials like crop residue and animal waste, is an example of renewable energy from biomass.

Q: Define the term 'mineral resources.'

A: Mineral resources are naturally occurring substances found beneath the earth's surface and include metals, non-metals, and fossil fuels.

Q: How can we ensure the sustainable use of mineral resources?

A: Sustainable use can be ensured by using minerals efficiently, recycling, reducing wastage, and adopting environmentally friendly mining practices.

Q: What is the purpose of the '3 R' approach (Reduce, Reuse, and Recycle)?

A: The '3 R' approach aims to minimize waste generation, maximize resource efficiency, and reduce the burden on natural resources.

Q: Explain the concept of 'rainwater harvesting.'

A: Rainwater harvesting involves collecting and storing rainwater for future use, primarily to recharge groundwater and supplement water supply.

Q: Why is it important to reduce, reuse, and recycle paper?

A: Reducing paper usage helps conserve trees and energy, reusing paper extends its lifespan, and recycling paper decreases the demand for fresh paper production.

Q: How can we prevent the pollution of rivers and lakes?

A: Pollution can be prevented by treating industrial waste, using eco-friendly cleaning products, avoiding littering, and treating sewage before disposal.

Q: Name two natural disasters that can be caused by deforestation.

A: Deforestation can lead to landslides and flash floods due to soil erosion and disruption of the natural water cycle.

Q: What are the advantages of using wind energy?

A: Wind energy is clean, renewable, abundant, and reduces dependence on fossil fuels, thus contributing to a healthier environment.

Q: Define the term 'ecosystem.'

A: An ecosystem is a community of living organisms (plants, animals, and microorganisms) interacting with each other and their physical environment.

Q: How can we conserve energy in our daily lives?

A: Conserving energy can be achieved by switching off lights when not in use, using energy-efficient appliances, and minimizing unnecessary heating and cooling.

Q: Explain how planting more trees can help reduce air pollution.

A: Trees absorb carbon dioxide through photosynthesis, release oxygen, and act as natural filters, removing pollutants from the air.

Q: What do you understand by the term 'biodiversity'?

A: Biodiversity refers to the variety of life forms, including plants, animals, and microorganisms, found in a particular habitat or on Earth as a whole.

Q: What are the negative impacts of excessive use of chemical fertilizers and pesticides?

A: Excessive use of chemical fertilizers and pesticides can lead to soil degradation, water pollution, harm to beneficial organisms, and health risks.

Q: How can we manage electronic waste (e-waste) responsibly?

A: Responsible management of e-waste involves recycling electronic devices, properly disposing of hazardous components, and promoting sustainable manufacturing practices.

Q: Why is it important to protect and conserve wildlife?

A: Wildlife plays a crucial role in maintaining ecological balance, preserving biodiversity, pollination, and supporting various ecosystems.

Q: How does the human population explosion affect natural resources?

A: Rapid population growth increases the demand for resources, leading to overconsumption, resource depletion, and environmental degradation.

Q: What are the alternative sources of fuel that can reduce our reliance on fossil fuels?

A: Alternative sources include solar energy, wind energy, hydroelectric power, biofuels, and geothermal energy.

Q: How can we prevent soil erosion?

A: Soil erosion can be prevented by practicing terrace farming, contour plowing, crop rotation, and afforestation.

Q: What is the role of the government in the management of natural resources?

A: The government should enforce policies, regulations, and laws to ensure the sustainable use and conservation of natural resources.

Q: How can water pollution be controlled?

A: Water pollution can be controlled through proper sewage treatment, industrial waste management, and avoiding the release of pollutants into water bodies.

Q: Define the term 'recharge of groundwater.'

A: Recharge of groundwater refers to the process of replenishing underground water sources by allowing rainwater to percolate through the soil.

Q: Why is renewable energy considered more sustainable than non-renewable energy sources?

A: Renewable energy sources can be replenished naturally and do not deplete over time, unlike non-renewable sources like fossil fuels.

Q: How can we conserve and manage our forests efficiently?

A: Efficient forest management includes afforestation, reforestation, conservation of forest cover, preventing illegal logging, and involving local communities.

Q: What are the negative consequences of excessive groundwater extraction?

A: Excessive groundwater extraction can lead to sinking of land, depletion of aquifers, saltwater intrusion, and loss of natural springs.

Q: How can the energy obtained from biomass be harnessed?

A: Energy from biomass can be harnessed through methods like the production of biogas, biofuels, and the generation of electricity from plant residues.

Q: What are the advantages of using solar energy?

A: Solar energy is abundant, non-polluting, sustainable, and can be harnessed at both small and large scales.

Q: How can we promote sustainable agriculture?

A: Sustainable agriculture involves promoting organic farming, minimizing the use of chemicals, conserving water, and adopting climate-smart techniques.

Q: Define the term 'desertification.'

A: Desertification refers to the process of fertile land turning into desert or arid areas due to human activities, climatic changes, and soil degradation.

Q: Why is soil conservation important in agriculture?

A: Soil conservation is crucial to prevent soil erosion, maintain soil fertility, minimize water runoff, and sustain agricultural productivity.

Q: Explain the concept of 'reuse' in waste management.

A: Reuse involves using an item multiple times or in creative ways, extending its lifespan, and reducing the need for new production.

Q: What is the role of youth in promoting the sustainable management of natural resources?

A: Youth can play a significant role by raising awareness, adopting sustainable practices, encouraging conservation, and advocating for policy changes.

Q: How does the excessive use of synthetic fertilizers affect soil health?

A: Overuse of synthetic fertilizers can degrade soil quality, decrease microbial activity, and adversely affect beneficial organisms.

Q: How can we reduce the pollution caused by vehicles?

A: Pollution from vehicles can be reduced by promoting public transportation, using electric vehicles, carpooling, and adhering to emission regulations.

Q: What are the harmful effects of air pollution on human health?

A: Air pollution can cause respiratory problems, allergies, cardiovascular diseases, and other health issues, especially in vulnerable populations.

Q: How can we conserve and sustainably manage marine resources?

A: Conservation efforts include establishing marine protected areas, controlling overfishing, implementing sustainable fishing practices, and reducing pollution.

Q: What measures can be taken to prevent soil degradation?

A: Measures include practicing soil conservation techniques, adopting organic farming, avoiding overgrazing, and maintaining adequate ground cover.

Q: Why is it important to conserve and manage water resources?

A: Water resources need to be conserved and managed to meet the present and future needs of human beings, agriculture, and ecosystem health.

Q: What are the economic benefits of conserving natural resources?

A: Conserving natural resources can generate revenue through ecotourism, sustainable industries, and the preservation of biodiversity.

Q: How does climate change impact the availability and distribution of natural resources?

A: Climate change affects the quantity and quality of water resources, causes shifts in ecosystems, and can disrupt the availability of certain resources.

Chapter 1 Real Numbers

What is a real number?

Define rational numbers.

Give an example of an irrational number.

Can zero be considered a real number? Why or why not?

What is a natural number?

Is the number 0 a natural number?

Are all integers also rational numbers? Explain.

Write two irrational numbers between 0.5 and 0.7.

Express 3/5 as a decimal.

State the Euclidean division lemma.

Explain the concept of a terminating decimal.

Determine if the following numbers are rational or irrational: ?3, 0.75, and

?.

Find 4/7 as a recurring decimal.

What is a prime number? Give an example.

Explain the concept of a composite number.

Find the prime factors of 36.

Determine the HCF of 24 and 36.

What is a co-prime pair of numbers? Give an example.

Find the LCM of 8 and 12.

Find the HCF and LCM of 15 and 25.

Simplify: 6/12 + 3/4.

Find the value of ?100.

What is the value of 0.75 as a fraction in simplest form?

Determine the value of (–5) × (–8) × 6.

Simplify: (2^3 × 2^4) ÷ 2^2.

Solve: 5x – 3 = 22.

If a + b = 12 and b = 5, find the value of a.

Solve: ?(x + 4) = 7.

If the perimeter of a rectangle is 26 cm and one side measures 6 cm, find the length of the other side.

Find the value of x in the equation 3^x = 27.

What is the sum of the first 10 prime numbers?

Simplify: (3^2 × 5^3) ÷ (3^4 × 5^2).

Solve: 4x + 3 = 27.

Find the value of x in the equation 2x – 3 = 13.

If 20% of a number is 12, find the number.

Solve: 5x + 2 = 4x + 9.

Find the square root of 225.

What is the value of 63 – 48 + 58 – 24?

Simplify: (4^3 × 2^4) ÷ (2^2 × 4^2).

Find the value of x in the equation 5(x - 3) = 40.

Solve: 2(x + 4) = 20.

If 2x + 3 = 15, find the value of x.

Simplify: ?(25^2 ÷ 5^2).

Find the value of x in the equation 3(x + 2) + 5 = 26.

If a^2 = 169, find the value of a.

Simplify: ?(16 × 49).

Find the value of x in the equation 2(x - 3) = 14.

If 7x + 5 = 40, find the value of x.

Simplify: 4^2 × (2^3 ÷ 2^2).

Find the value of x in the equation 5x + 3 = 18.

Chapter 2 Polynomials

Define a polynomial.

What is the degree of a polynomial?

Give an example of a monomial.

State two polynomial expressions of degree 2.

How many terms are there in a binomial expression?

What is the constant term in a polynomial?

Find the degree of the polynomial 5x^3 - 2x^2 + 7x - 1.

Simplify the expression: (2x + 3)(3x - 5).

Is x^3 + 3x^2 - x - 2 a polynomial? If yes, mention its degree.

Determine the value of a in the polynomial expression ax^2 + 5x - 2 when the degree is 2.

Subtract (4x - 2) from (7x + 3).

Find the sum of 3x^2 + 2x - 1 and x^2 + 4x + 3.

What is the coefficient of the term 5x^3 in the expression 3x^4 - 2x^3 + 5x^2 - 4x + 1?

How many terms are there in the polynomial (x + 2y - 3z)^4?

Evaluate 2x^3 + 5x^2 - 3x + 4 at x = 2.

Simplify: [(x^2 - 3x) + (2x^3 + 5x)] - (4x^2 - 2x).

Divide the polynomial 2x^3 + 3x^2 - 5x + 4 by x - 2.

Find a polynomial that has 5 as one of its solutions.

Determine whether x + 2 is a factor of the polynomial 2x^2 + 5x + 10.

Factorize the polynomial x^2 + 7x + 10.

Solve the equation x^2 - 5x + 6 = 0.

Determine the roots of the quadratic equation 3x^2 + 2x - 1 = 0.

Find the value of k so that x - k is a factor of the polynomial x^3 + 3x^2 - 2x - k.

Multiply (3x + 4)(2x - 5) using the distributive property.

Determine the remainder when (2x^3 - 3x + 5) is divided by (x + 2).

Find the product of the factors of the polynomial x^2 - 4.

Express the polynomial (2x^3 + 3x^2 - 5x + 4)^2 as a product of two binomials.

Solve the equation x^3 - 6x^2 + 11x - 6 = 0 given that one of its roots is 2.

Find the area of a square whose side length is represented by the polynomial 5x + 2.

Determine the zeroes of the polynomial x^3 - 2x^2 - 11x + 12.

Simplify the expression: (x^2 + 4) (x^4 - x^2 + 1).

Find the value of p if (x - p) is a factor of the polynomial x^3 - 4x^2 + 3x + 6.

Express the polynomial (x + 1)(x - 2)(x + 3) in standard form.

Solve the equation x^2 - 8x - 20 = 0 using the quadratic formula.

Find the value of k if (x - 2) is a factor of the polynomial 2x^3 + 3x^2 - 4x + k.

Factorize the polynomial x^3 - 4x^2 + 4x - 1.

Determine the value of a and b in (x + 2)(x - 3) = x^2 + ax + b.

Simplify the expression: (2x^2 + 3x - 1) - (x^2 - 5x + 2).

Find the product of the roots of the quadratic equation 2x^2 + 7x - 10 = 0.

Determine the possible number of roots for the equation x^4 - 3x^2 + 2 = 0.

Simplify the expression: (x^3 + 5x^2 - 3x) + (2x^3 - 4x^2 + 7x).

Find the remainder when x^3 + 2x^2 - 5 is divided by (x - 2).

Calculate the value of a in the equation x^2 + ax + 9 = 0, given that the sum of the roots is -5.

Determine the value of p if (x + p) is a factor of the polynomial x^3 + 3x^2 - 2x - 10.

Simplify the expression: (3x^2 - 4) (5x + 2) - 2(4x^2 - 3x + 5).

Factorize the polynomial x^3 - 8y^3.

Find the zeroes of the polynomial x^3 - 2x^2 - x + 2 and verify the relationship between the zeroes and coefficients.

Determine the value of p if (x + p) is a factor of the polynomial x^3 + 2x^2 - 3x - 10.

Factorize the polynomial 4x^3 - 12x^2 + 8x.

Find the value of n if (x + 1)(x - 2)(x - n) = x^3 + x^2 - 8x - 12.

Chapter 3 Pair of Linear Equations in Two Variables

Q. Define a pair of linear equations in two variables.

Q. State the importance of solving a pair of linear equations.

Q. What is the graphical representation of a pair of linear equations?

Q. How many solutions can a pair of linear equations have?

Q. Define consistent and inconsistent systems of equations.

Q. Differentiate between independent and dependent systems of equations.

Q. How can you determine whether a given pair of equations is consistent or inconsistent?

Q. Explain how to solve a pair of linear equations by the method of substitution.

Q. Solve the pair of equations: 2x + 3y = 10 and x - y = 4 using substitution method.

Q. What is the method of elimination to solve a pair of linear equations?

Q. Solve the equations: 3x + 4y = 5 and 2x - 3y = 1 using elimination method.

Q. Explain the concept of cross-multiplication in solving linear equations.

Q. Solve the equations: 5x + 2y = 11 and 3x - 4y = 7 using cross-multiplication method.

Q. How can you verify the solution of a pair of linear equations?

Q. Determine the values of x and y in the equations: 4x - 5y = 3 and 2x + 3y = 1 using the verification method.

Q. What is meant by the substitution method of solving a pair of equations algebraically?

Q. Solve the pair of equations: 3x + 2y = 8 and 4y - 5x = 7 using the substitution method.

Q. Explain the steps involved in graphically solving a pair of equations.

Q. Graphically solve the equations: 2x + 3y = 9 and 4x - y = 7.

Q. How can you solve a pair of linear equations using the elimination method?

Q. Solve the equations: 5x + 4y = 10 and 3x - 2y = 5 using the elimination method.

Q. Define the concept of consistency in a pair of linear equations represented graphically.

Q. Solve the equations: 3x + 2y = 12 and 6x + 4y = 24 using graph representation.

Q. Explain the concept of inconsistency in a pair of linear equations represented graphically.

Q. Solve the pair of equations: 2x - 3y = 5 and 4x - 6y = 12 graphically.

Q. How can you find the solutions of linear equations using the cross-multiplication method?

Q. Solve the equations: x - 2y = 3 and 2x - 4y = 6 using cross-multiplication.

Q. Define the term "simultaneous equations."

Q. Solve the pair of equations: 3x + 4y = 11 and 6x + 8y = 22 using simultaneous equations.

Q. Explain the concept of dependent consistent equations.

Q. Solve the equations: 2x + 3y = 6 and 4x + 6y = 12, and verify its solution.

Q. Define the concept of independent consistent equations.

Q. Solve the equations: 5x - y = 3 and -3x + y = 1, and verify its solution.

Q. How can you find the solution of dependent inconsistent equations?

Q. Solve the equations: 5x + 2y = 7 and 10x + 4y = 14, and verify its solution.

Q. Define the concept of independent inconsistent equations.

Q. Solve the equations: 3x + 2y = 6 and 6x + 4y = 11, and verify its solution.

Q. Explain the concept of unique solution in a pair of linear equations.

Q. Solve the pair of equations: 4x + 5y = 16 and 2x + 3y = 8, and verify its unique solution.

Q. Define the concept of infinitely many solutions in a pair of linear equations.

Q. Solve the equations: 3x - 4y = 5 and 6x - 8y = 10, and verify its infinitely many solutions.

Q. Explain how the substitution method is applicable for dependent consistent equations.

Q. Solve the equations: 2x + y = 5 and 4x + 2y = 10 using the substitution method.

Q. Explain how the elimination method is applicable for dependent inconsistent equations.

Q. Solve the equations: 3x + 5y = 8 and 6x + 10y = 16 using the elimination method.

Q. Define the concept of "No Solution" in a pair of linear equations.

Q. Solve the pair of equations: 3x + 5y = 9 and 6x + 10y = 18 algebraically and explain why it has no solution.

Q. Explain the relationship between the number of lines represented by the equations and their solutions.

Q. Determine the number of solutions in the pair of equations: 4x + 7y = 10 and 8x + 14y = 20.

Q. Explain how to determine the number of solutions using the graphical method.

Chapter 4 Quadratic Equations

Q. What is a quadratic equation?

Q. Write the general form of a quadratic equation.

Q. What is the degree of a quadratic equation?

Q. Name the three forms of quadratic equations.

Q. What is the standard form of a quadratic equation?

Q. How many solutions can a quadratic equation have?

Q. State the zero-product property.

Q. How can a quadratic equation be solved using factoring?

Q. Solve the equation: x^2 + 5x = 14.

Q. Solve the equation: 2x^2 + 3x = 0.

Q. How can the square root property be used to solve quadratic equations?

Q. Solve the equation: x^2 - 16 = 0.

Q. Solve the equation: 2x^2 - 9 = 0.

Q. State the quadratic formula.

Q. Solve the equation: 4x^2 - 5x + 1 = 0 using the quadratic formula.

Q. Solve the equation: 3x^2 + 2x - 1 = 0 using the quadratic formula.

Q. What should be considered while deciding the method to solve a quadratic equation?

Q. Explain the concept of discriminant.

Q. How can the discriminant be used to determine the nature of the solutions?

Q. Find the discriminant of the equation: 2x^2 - 3x + 1 = 0.

Q. Find the discriminant of the equation: x^2 + 8x + 16 = 0.

Q. What is the nature of the solutions if the discriminant is zero?

Q. What is the nature of the solutions if the discriminant is positive?

Q. What is the nature of the solutions if the discriminant is negative?

Q. How can the quadratic formula be derived using completing the square method?

Q. Solve the equation: 3x^2 + 4x - 1 = 0 using the completing the square method.

Q. Solve the equation: 2x^2 + 5x + 3 = 0 using the completing the square method.

Q. Explain the concept of imaginary solutions.

Q. Solve the equation: x^2 + 4 = 0, using imaginary solutions.

Q. Solve the equation: 3x^2 - 4 = 0, using imaginary solutions.

Q. Explain the concept of roots of a quadratic equation.

Q. Find the roots of the equation: 2x^2 + 3x - 2 = 0.

Q. Find the roots of the equation: x^2 - 10x + 25 = 0.

Q. How can the sum and product of roots of a quadratic equation be related to its coefficients?

Q. Find the sum and product of roots for the equation: 4x^2 - 5x + 1 = 0.

Q. Find the sum and product of roots for the equation: 2x^2 + 7x + 3 = 0.

Q. Explain the concept of the quadratic graph.

Q. How can the vertex formula be used to find the vertex of a quadratic equation?

Q. Find the vertex of the equation: y = x^2 + 4x - 5.

Q. Find the vertex of the equation: y = -2x^2 + 6x - 3.

Q. State the axis of symmetry for a quadratic graph.

Q. Find the axis of symmetry for the equation: y = 2x^2 - 8x + 6.

Q. Find the axis of symmetry for the equation: y = -3x^2 + 9x - 4.

Q. How does the leading coefficient affect the shape of a quadratic graph?

Q. Sketch the graph of the equation: y = x^2 - 4.

Q. Sketch the graph of the equation: y = -2x^2 + 3x + 1.

Q. State the maximum or minimum point of a quadratic graph.

Q. Find the maximum or minimum point for the equation: y = -x^2 + 6x - 9.

Q. Find the maximum or minimum point for the equation: y = 3x^2 - 2x + 7.

Q. What are the applications of quadratic equations in real-life scenarios?

Chapter 5 Arithmetic Progressions

Q. Define an arithmetic progression.

Q. What is the common difference in an arithmetic progression?

Q. Write the first three terms of an arithmetic progression with common difference 4.

Q. Find the 10th term of an arithmetic progression with first term 3 and common difference 2.

Q. Determine the common difference if the first term of an arithmetic progression is 7 and the 5th term is 22.

Q. Find the sum of the first 10 terms of an arithmetic progression with first term 2 and common difference 3.

Q. In an arithmetic progression, the 20th term is 55 and the 1st term is 8. Find the common difference.

Q. Find the 15th term in an arithmetic progression if the 8th term is 32 and the common difference is 2.

Q. What is the formula to find the nth term of an arithmetic progression?

Q. State the formula to find the sum of the first n terms of an arithmetic progression.

Q. If the first term of an arithmetic progression is 5 and the common difference is -3, find the third term.

Q. Find the sum of all odd numbers between 10 and 30.

Q. In an arithmetic progression, if the sum of the first 7 terms is 84 and the common difference is 6, find the first term.

Q. The first term of an arithmetic progression is 12 and the common difference is 5. Find the 20th term.

Q. Find the number of terms in an arithmetic progression with first term 1, last term 101, and common difference 1.

Q. If the sum of the first 12 terms of an arithmetic progression is 132 and the common difference is 3, find the first term.

Q. In an arithmetic progression, the 3rd term is 12 and the 10th term is 37. Find the common difference.

Q. Find the sum of all numbers between 50 and 100 which are divisible by 7.

Q. Determine the 6th term of an arithmetic progression if the sum of the first 6 terms is 39 and the common difference is 3.

Q. The 10th term of an arithmetic progression is 27 and the common difference is -2. Find the first term.

Q. Find the sum of the first 25 terms of an arithmetic progression with first term 4 and common difference 2.

Q. In an arithmetic progression, the 1st term is 10 and the 12th term is 70. What is the common difference?

Q. Find the number of terms in an arithmetic progression with first term 5, common difference 3, and last term

Q.

Q. The first term of an arithmetic progression is -6 and the common difference is 4. Find the 15th term.

Q. If the sum of the first n terms of an arithmetic progression is given by Sn = n/2 (2a + (n-1)d), where a is the first term and d is the common difference, find the 4th term of the arithmetic progression -3, 2, 7, 12, ...

Q. In an arithmetic progression, the sum of the first 5 terms is 50 and the common difference is 2. Find the 1st term.

Q. Find the sum of all even numbers between 20 and 60.

Q. The 5th term of an arithmetic progression is -8 and the common difference is -3. Find the first term.

Q. What is the sum of all integers from 1 to 100?

Q. Find the number of terms in an arithmetic progression with first term 2, last term 98, and common difference 4.

Q. The first term of an arithmetic progression is 9 and the common difference is 6. Find the 12th term.

Q. In an arithmetic progression, the first term is 3 and the 6th term is 23. Determine the common difference.

Q. Find the sum of all natural numbers between 30 and 80.

Q. If the sum of the first n terms of an arithmetic progression is given by Sn = n/2 (a + l), where a is the first term and l is the last term, find the last term of the arithmetic progression 10, 16, 22, ...

Q. The 7th term of an arithmetic progression is 31 and the common difference is 3. Find the first term.

Q. Determine the sum of all multiples of 9 between 20 and 100.

Q. Find the number of terms in an arithmetic progression with first term 7, common difference 2, and last term 77.

Q. The first term of an arithmetic progression is -1 and the common difference is -4. Find the 25th term.

Q. In an arithmetic progression, the 2nd term is 10 and the 7th term is 45. Find the common difference.

Q. Find the sum of the first 20 even numbers.

Q. The first term of an arithmetic progression is 3 and the common difference is -1. Find the sum of the first 15 terms.

Q. In an arithmetic progression, the first term is 4 and the 8th term is 30. Determine the common difference.

Q. Find the sum of all numbers between 100 and 150 which are divisible by 8.

Q. The 3rd term of an arithmetic progression is 10 and the common difference is 2. Find the first term.

Q. Determine the sum of all odd numbers between 20 and 40.

Q. Find the number of terms in an arithmetic progression with first term -5, last term 115, and common difference 10.

Q. The first term of an arithmetic progression is 7 and the common difference is 3. Find the 20th term.

Q. In an arithmetic progression, if the sum of the first 10 terms is 160 and the common difference is 4, find the first term.

Q. Find the sum of the first 30 terms of an arithmetic progression with first term 1.5 and common difference 0.5.

Q. The 9th term of an arithmetic progression is 14 and the common difference is -2. Find the first term.

Chapter 6 Triangles

Q. Define a triangle.

Q. What is the sum of the angles of a triangle?

Q. State the two types of triangles based on sides.

Q. What is an equilateral triangle?

Q. What is an isosceles triangle?

Q. What is a scalene triangle?

Q. Define an acute-angled triangle.

Q. Define a right-angled triangle.

Q. Define an obtuse-angled triangle.

Q. What is the Pythagorean theorem?

Q. State the converse of the Pythagorean theorem.

Q. How can you determine if three given sides form a triangle?

Q. What is the perimeter of a triangle?

Q. State the area formula for a triangle.

Q. How do you find the height of a triangle?

Q. What is the relation between the area of two similar triangles?

Q. State the angle sum property of a triangle.

Q. What is the exterior angle property of a triangle?

Q. Define the median of a triangle.

Q. Define the altitude of a triangle.

Q. State the inequality theorem for triangles.

Q. Can a triangle have two right angles?

Q. Can a triangle have two obtuse angles?

Q. Can a triangle have two acute angles?

Q. How many medians does a triangle have?

Q. How many altitudes does a triangle have?

Q. State the similarity criterion for triangles.

Q. Define congruent triangles.

Q. How many congruence criteria are there for triangles?

Q. State the SSS congruence criterion.

Q. State the SAS congruence criterion.

Q. State the ASA congruence criterion.

Q. State the RHS congruence criterion.

Q. Define the centroid of a triangle.

Q. Define the circumcenter of a triangle.

Q. Define the incenter of a triangle.

Q. Define the orthocenter of a triangle.

Q. Define the Euler line in a triangle.

Q. What is the sum of the lengths of any two sides of a triangle?

Q. State the ratio of the areas of two similar triangles.

Q. Explain the concept of similar triangles.

Q. Define the right bisector of a triangle.

Q. Define the perpendicular bisector of a triangle.

Q. Define the angle bisector of a triangle.

Q. State the ratio of the corresponding sides of two similar triangles.

Q. How can you determine if two triangles are similar?

Q. What is the sum of the lengths of any two sides of a triangle compared to the length of the third side?

Q. Define the circumradius of a triangle.

Q. Define the inradius of a triangle.

Q. Explain how to find the length of an altitude in a triangle.

Chapter 7 Coordinate Geometry

Q. What is the coordinate plane?

Q. What are the two axes in the coordinate plane called?

Q. What is the origin of the coordinate plane?

Q. How are points represented in coordinate geometry?

Q. What is the difference between the x-coordinate and the y-coordinate?

Q. What is the distance formula between two points on a coordinate plane?

Q. How do you find the midpoint between two points on a coordinate plane?

Q. What are the coordinates of the midpoint of the line segment joining (-2, 3) and (4, 5)?

Q. How do you determine if three points on a coordinate plane are collinear?

Q. What is the slope of a line on a coordinate plane?

Q. How do you calculate the slope of a line given two points?

Q. What is the slope-intercept form of a linear equation?

Q. What is the equation of a horizontal line?

Q. What is the equation of a vertical line?

Q. How do you find the equation of a line given its slope and a point on the line?

Q. What is the x-intercept of a line?

Q. What is the y-intercept of a line?

Q. What does it mean for two lines to be parallel?

Q. How do you determine if two lines are parallel or perpendicular?

Q. What does it mean for two lines to be perpendicular?

Q. How do you find the distance between a point and a line on a coordinate plane?

Q. Find the equation of a line that is parallel to the x-axis and passes through the point (3, -2).

Q. Find the equation of a line that is perpendicular to the y-axis and passes through the point (-5, 2).

Q. How do you find the area of a triangle with vertices on a coordinate plane?

Q. How do you find the perimeter of a polygon with vertices on a coordinate plane?

Q. What is the formula for the slope of a line passing through two points, (x1, y1) and (x2, y2)?

Q. Determine the slope of the line passing through (-3, 4) and (5, -2).

Q. Find the coordinates of the point that divides the line segment joining (-1, 3) and (7, 5) in the ratio 2:3 internally.

Q. Find the coordinates of the point that divides the line segment joining (3, -2) and (-5, 6) in the ratio 3:4 externally.

Q. Find the distance between the points (4, -2) and (-1, -6).

Q. Determine if the points (2, -3), (1, 0), and (-2, 5) are collinear.

Q. If the slope of a line is 3/4, what is the slope of a line parallel to it?

Q. If a line has a slope of -2, what is the slope of a line perpendicular to it?

Q. Find the area of a triangle with vertices (0, 0), (3, 4), and (5, 2).

Q. Find the perimeter of a quadrilateral with vertices (2, 1), (4, 5), (8, 6), and (5, 3).

Q. Determine the equation of a line with slope 2 and passing through the point (1, -3).

Q. Determine the equation of a line with slope -1/2 and passing through the point (4, 7).

Q. What is the x-intercept of the line 3x + 2y = 6?

Q. What is the y-intercept of the line 5x - 4y = 12?

Q. Find the distance between the line 2x - 3y = 6 and the point (4, -1).

Q. Find the coordinates of the midpoint between the points (-1, 2) and (3, -4).

Q. Determine the equation of a line parallel to the y-axis and passing through the point (2, 5).

Q. Determine the equation of a line perpendicular to the x-axis and passing through the point (-3, -2).

Q. How many quadrants are there in a coordinate plane?

Q. What are the coordinates of the origin?

Q. What is the equation of the x-axis?

Q. What is the equation of the y-axis?

Q. Find the slope of the line passing through (1, 2) and (-3, 5).

Q. Find the area of a triangle with vertices (0, 0), (6, 0), and (3, 4).

Q. Find the perimeter of a parallelogram with vertices (1, 2), (4, 1), (7, 3), and (4, 4).

Chapter 8 Introduction to Trigonometry

Q. Define trigonometry in simple words.

Q. What is the difference between angle and arc?

Q. State the Pythagorean theorem.

Q. What is the meaning of the term "sine" in trigonometry?

Q. How can you find the value of cosine of an angle?

Q. Define tangent of an angle.

Q. What is the value of sine 90 degrees?

Q. How is the value of cosine 0 degrees calculated?

Q. Explain the concept of opposite and adjacent sides in a right-angled triangle.

Q. What is the relation between sine and cosine?

Q. State the value of tangent 45 degrees.

Q. How can you find the value of sine 60 degrees?

Q. Define the term "co-terminal angles."

Q. How are the values of secant and cosecant related to cosine and sine?

Q. What does the term "trigonometric ratios" mean?

Q. Explain how to find the value of tangent 30 degrees.

Q. How are trigonometric ratios used to find side lengths in a right-angled triangle?

Q. Define the term "angle of elevation."

Q. How can you determine the height of a tower using trigonometry?

Q. Explain the concept of the angle of depression.

Q. How can you find the distance between two objects using angle of elevation and angle of depression?

Q. Define the term "complementary angles."

Q. What is the sum of the angles of a triangle?

Q. In a right-angled triangle, what is the relation between the three sides and the three angles?

Q. Define the term "hypotenuse."

Q. Explain how to find the height of an object using the concept of similar triangles.

Q. State the difference between acute, right, and obtuse angles.

Q. What is the value of cotangent 60 degrees?

Q. How can you find the value of cosecant 45 degrees?

Q. Explain the concept of "angle of inclination."

Q. What is the relation between the angle of inclination and the slo

pe of a line?

Q. Define the term "radial distance."

Q. What is the meaning of an angle measured in radians?

Q. How can you convert degrees to radians?

Q. Explain the concept of the unit circle.

Q. What is the relation between the radius of a circle and its circumference?

Q. Define the term "arc length."

Q. How can you calculate the value of an angle in radians?

Q. State the relation between the circumference and diameter of a circle.

Q. Explain how to find the value of sine 45 degrees using the unit circle.

Q. Define the term "angle of rotation."

Q. How can you find the value of cosine 30 degrees using the unit circle?

Q. Explain the concept of angular velocity.

Q. What is the meaning of the term "periodic functions" in trigonometry?

Q. Define the term "amplitude" in trigonometric functions.

Q. How can you find the value of secant 60 degrees using the unit circle?

Q. State the relation between the amplitude and frequency of a trigonometric function.

Q. What is the meaning of the term "phase shift" in trigonometry?

Q. Define the term "period" in trigonometric functions.

Q. How are trigonometric functions used to model real-life phenomena?

Chapter 9 Some Applications of Trigonometry

Q. What is the angle of elevation?

Q. Define the angle of depression.

Q. What is the height of an object if the angle of elevation is 30 degrees and the distance from the object is 10 meters?

Q. How do we measure the height of a tall building using the concept of trigonometry?

Q. What are the applications of trigonometry in real life?

Q. How can we find the distance between two points using trigonometry?

Q. State the Pythagorean theorem.

Q. If the base and height of a right-angled triangle are given, how can we find the hypotenuse length using trigonometry?

Q. What are the different trigonometric ratios?

Q. If the hypotenuse and one angle of a right-angled triangle are given, how can we find the lengths of the other two sides?

Q. How do we find the value of sin 30 degrees?

Q. What is the value of cos 60 degrees?

Q. Define the concept of radian measure.

Q. What is the formula for calculating the area of a triangle?

Q. How is the concept of trigonometry used in navigation?

Q. Explain the concept of GPS using trigonometry.

Q. How can we find the distance between two cities using trigonometry?

Q. What is the concept of tangent and cotangent?

Q. Define the equation of a circle.

Q. How can we find the distance between two ships at sea using trigonometry?

Q. Explain the concept of bearings using trigonometry.

Q. How can we find the height of a tower using trigonometry if the angle of elevation from two different points is given?

Q. What is the angle of depression if you are looking down at a well from a height?

Q. How do we find the length of a shadow using trigonometry?

Q. What is the formula for calculating the area of a sector?

Q. Explain the concept of time periods and frequency using trigonometry.

Q. How can we find the width of a river using trigonometry if the distance and angles are given?

Q. What is the difference between simple interest and compound interest?

Q. What are the applications of trigonometry in architecture and construction?

Q. Explain the concept of the unit circle.

Q. What are the different types of trigonometric identities?

Q. How can we find the distance between two poles using trigonometry if their heights and angles of elevation are given?

Q. What is the concept of trigonometric ratios in a right-angled triangle?

Q. How can we find the distance between two buildings using trigonometry if their heights and angles of depression are given?

Q. Explain the concept of angular velocity using trigonometry.

Q. How do we calculate the value of cos 45 degrees?

Q. If the opposite side and the hypotenuse of a right-angled triangle are given, how can we find the adjacent side?

Q. What is the formula for calculating the area of a rectangle?

Q. How can we find the distance between two cars using trigonometry if the angle between the two lines of sight is given?

Q. Explain the concept of periodic functions using trigonometry.

Q. How do we calculate the value of sin 60 degrees?

Q. What are the different properties of trigonometric ratios?

Q. How can we find the distance between two buildings using trigonometry if their heights and angles of elevation are given?

Q. What is the concept of phase difference in trigonometry?

Q. How can we use trigonometry to calculate the length of a ladder required to reach a certain height?

Q. Explain the concept of amplitude in trigonometry.

Q. What is the shortest distance between two points on the surface of the earth called?

Q. How do we find the value of tan 45 degrees?

Q. What is the concept of angular displacement in trigonometry?

Q. How can we find the altitude of a satellite using trigonometry if the distance and angle of elevation are given?

Chapter 10 Circles

Q. What is a circle?

Q. Define the radius of a circle.

Q. Define the diameter of a circle.

Q. How is the radius related to the diameter of a circle?

Q. What is the circumference of a circle?

Q. What is the formula to calculate the circumference of a

circle?

Q. What is the area of a circle?

Q. What is the formula to calculate the area of a circle?

Q. How can you find the diameter of a circle if the circumference is given?

Q. How can you find the radius of a circle if the circumference is given?

Q. How can you find the area of a circle if the radius is given?

Q. How can you find the area of a circle if the diameter is given?

Q. What is a chord in a circle?

Q. What is the difference between a chord and a diameter?

Q. What is a secant in a circle?

Q. What is a tangent in a circle?

Q. What is an arc in a circle?

Q. What is the difference between a minor arc and a major arc?

Q. What is a central angle in a circle?

Q. What is an inscribed angle in a circle?

Q. State the angle formed by the radius and tangent at a point on a circle.

Q. State the angle formed by the chord and the tangent at a point on a circle.

Q. What is the relationship between the central angle and the inscribed angle?

Q. Define the angle subtended by an arc at the center of a circle.

Q. Define the angle subtended by an arc at any point on the circle.

Q. State the relationship between the angles subtended by the same arc at the center and any point on the circle.

Q. Define a cyclic quadrilateral.

Q. State the sum of opposite angles of a cyclic quadrilateral.

Q. What is the relationship between the opposite angles of a cyclic quadrilateral?

Q. What is the relationship between the angles of a cyclic quadrilateral and the angles in its interior?

Q. Define a tangential quadrilateral.

Q. What is the relationship between the opposite sides of a tangential quadrilateral?

Q. Define the radius of a circle inscribed in a triangle.

Q. Define the radius of a circle circumscribing a triangle.

Q. What is the relationship between the angles of a triangle and the angles subtended by the corresponding sides in a circle?

Q. Define the angle between a tangent and a chord.

Q. State the relationship between the angle between a tangent and a chord and the angle subtended by that chord in the alternate segment.

Q. In a circle, the chord AB is equal to its radius. Find the measure of the angle subtended by AB.

Q. In a circle, the tangent PT and a chord AB are drawn from an external point P. If the measure of angle PTB is 60 degrees, find the measure of angle APB.

Q. In a circle, if a chord AB is equal to its diameter, find the measure of angle ACB.

Q. In a circle, if the measure of angle subtended by an arc at the center is 120 degrees, find the measure of the corresponding inscribed angle.

Q. In a circle, if the measure of angle subtended by an arc at any point on the circle is 60 degrees, find the measure of the corresponding central angle.

Q. In a circle, if the measure of angle ACB is equal to its inscribed angle, find the measure of angle ACB.

Q. In a circle, if the angle subtended by an arc at any point on the circle is double the measure of the corresponding central angle, find the measure of the arc.

Q. In a circle, if an angle subtended by an arc is 90 degrees, find the measure of the corresponding central angle.

Q. In a circle, if an angle subtended by an arc is 30 degrees, find the measure of the corresponding inscribed angle.

Q. In a circle, if a tangent and a chord intersect at a point on the circle, find the measure of the angles formed by the tangent and the chord.

Q. In a circle, if two chords intersect internally, find the measure of the angles formed by the chords.

Q. In a circle, if a diameter and a chord are perpendicular to each other, find the measure of the angles formed by the diameter and the chord.

Q. In a circle, if a chord is equal to the radius, find the measure of the angles formed by the chord and the diameter.

Chapter 11 Constructions

Q. What is a construction in mathematics?

Q. Define the term "compass" in construction.

Q. What is a straightedge used for in construction?

Q. Explain the process of constructing an angle of 45 degrees.

Q. How can you construct a line segment equal to a given line segment?

Q. Describe the steps to construct an angle bisector.

Q. Can you construct a triangle with given sides of lengths 3 cm, 4 cm, and 7 cm? If yes, explain how.

Q. What is the perpendicular bisector of a line segment?

Q. Explain the process of constructing a perpendicular bisector of a line segment.

Q. How can you construct an equilateral triangle?

Q. What is the center of a circle called?

Q. Describe the steps to construct a circle with a given radius.

Q. Can you construct a triangle with given angles of 45 degrees, 60 degrees, and 75 degrees? If yes, explain how.

Q. What is the process of constructing a tangent to a circle from an external point called?

Q. How can you construct a tangents to a circle at a given point?

Q. Define the term "quadrilateral" in geometry.

Q. Explain the process of constructing a parallelogram.

Q. Describe the steps to construct a rectangle.

Q. Can you construct a rhombus with diagonals of lengths 8 cm and 6 cm? If yes, explain how.

Q. What is the process of constructing a square called?

Q. Define the term "perpendicular" in geometry.

Q. Explain the process of constructing a perpendicular from an external point to a given line.

Q. Describe the steps to construct a perpendicular from a point on a line.

Q. Can you construct a triangle with given sides of lengths 6 cm, 8 cm, and 10 cm? If yes, explain how.

Q. What is the process of constructing a triangle similar to a given triangle called?

Q. How can you construct a triangle similar to a given triangle, but with double the area?

Q. Define the term "median" in a triangle.

Q. Explain the process of constructing the medians of a triangle.

Q. Describe the steps to construct an altitude of a triangle.

Q. Can you construct an isosceles triangle with given base angles of 60 degrees? If yes, explain how.

Q. What is the process of constructing a regular hexagon called?

Q. Define the term "cyclic quadrilateral" in geometry.

Q. Explain the process of constructing an incircle for a given triangle.

Q. Describe the steps to construct an excenter of a triangle.

Q. Can you construct a triangle with given sides of lengths 4 cm, 5 cm, and 9 cm? If yes, explain how.

Q. What is the process of constructing a triangle with given sides and included angles called?

Q. How can you construct a triangle with given sides of lengths 3 cm, 6 cm, and 4 cm? If yes, explain how.

Q. Define the term "centroid" in a triangle.

Q. Explain the process of constructing the circumcenter of a triangle.

Q. Describe the steps to construct an isosceles trapezium.

Q. Can you construct a parallelogram with one angle measuring 90 degrees? If yes, explain how.

Q. What is the process of constructing a segment dividing another segment in a given ratio called?

Q. How can you construct a line parallel to a given line through a given point?

Q. Define the term "midpoint" of a line segment.

Q. Explain the process of constructing the midpoints of a line segment.

Q. Describe the steps to construct a square inside a circle.

Q. Can you construct a parallelogram with diagonals measuring 10 cm and 12 cm? If yes, explain how.

Q. What is the process of constructing a quadrilateral, given its sides and one diagonal?

Q. How can you construct a quadrilateral with given sides of lengths 7 cm, 4 cm, 5 cm, and 6 cm? If yes, explain how.

Q. Define the term "angle of elevation" in trigonometry.

Chapter 12 Areas Related to Circles

Q. What is the formula for the circumference of a circle?

Q. How is the radius of a circle related to its diameter?

Q. State the formula for the area of a circle.

Q. What is the relation between the radius and area of a circle?

Q. Define the term 'sector' of a circle.

Q. How do you find the area of a sector?

Q. What is the length of an arc of a circle?

Q. How do you find the length of an arc when the angle is given?

Q. What is a chord in a circle?

Q. How do you find the length of a chord?

Q. State the theorem relating the perpendicular from the center of a circle to a chord.

Q. What is the tangent to a circle?

Q. Define the tangent to a circle.

Q. How many tangents can a circle have?

Q. State the tangent-chord theorem.

Q. What is a cyclic quadrilateral?

Q. Define the term 'inscribed angle'.

Q. How do you find the measure of an inscribed angle?

Q. State the theorem relating the measure of an inscribed angle to the intercepted arc.

Q. Explain the concept of a concentric circle.

Q. Define the terms ' cyclic quadrilateral' and 'opposite angles'.

Q. How are the opposite angles in a cyclic quadrilateral related?

Q. What is the relationship between the angle subtended by an arc at the center and an angle subtended by the same arc at the circumference?

Q. Define the term 'common chord' of two intersecting circles.

Q. What is the relationship between the lengths of the two chords of intersecting circles?

Q. State the theorem of the lengths of the two tangents drawn from an external point to a circle.

Q. Explain the concept of 'tangent to a circle from an external point'.

Q. Define the term 'excentral angle'.

Q. How can you prove that the lengths of opposite sides of an excentral angle are equal?

Q. Explain the concept of a 'sector of a circle'.

Q. What is the measure of the angle subtended by a minor arc at the center of a circle?

Q. State the relationship between the angle subtended by an arc at the center and the angle subtended at the circumference.

Q. Define the term 'direct common tangent'.

Q. How many common tangents can two circles have?

Q. What is the relationship between the lengths of the two direct common tangents?

Q. Explain the concept of a 'chord of a circle'.

Q. What is the relation between the lengths of the two chords equidistant from the center of a circle?

Q. Define the term 'segment of a circle'.

Q. How do you find the area of a segment of a circle?

Q. State the formula to find the length of an arc.

Q. What is the relationship between the central angle of a circle and its corresponding arc?

Q. Define the term 'alternate segment theorem'.

Q. How can you prove the alternate segment theorem?

Q. Explain the concept of 'subtended angle'.

Q. What is the measure of an angle subtended by an arc of a semicircle?

Q. State the theorem relating the angle subtended by an arc of a semicircle.

Q. Define the term 'interior angle of a cyclic quadrilateral'.

Q. How do you find the measure of an interior angle of a cyclic quadrilateral?

Q. State the theorem relating the interior opposite angles of a cyclic quadrilateral.

Q. Explain the relation between angles subtended by equal chords at the center of a circle.

Chapter 13 Surface Areas and Volumes

Q. What is the difference between the surface area and volume of a shape?

Q. Define the term "cylinder" and give an example of a real-life object that resembles a cylinder.

Q. How do you calculate the lateral surface area of a cylinder?

Q. What is the formula to find the total surface area of a cube?

Q. Explain the concept of volume and give an example of an object with a fixed volume.

Q. What is the formula to find the volume of a cylinder?

Q. Define the term "cone" and give an example of a real-life object that resembles a cone.

Q. How do you calculate the slant height of a cone?

Q. Explain the concept of the curved surface area of a cone.

Q. Derive the formula for the volume of a cone.

Q. What is the base area of a pyramid?

Q. How is the total surface area of a pyramid calculated?

Q. Define the term "spherical object" and give an example of a real-life spherical object.

Q. What is the formula for finding the surface area of a sphere?

Q. How do you calculate the volume of a sphere?

Q. Explain how to find the area of a circle using its circumference.

Q. Give an example of a real-life object that resembles a sphere.

Q. What is the formula for finding the volume of a rectangular prism?

Q. How can you calculate the lateral surface area of a cuboid?

Q. Define the term "hemisphere" and give an example of a real-life object that resembles a hemisphere.

Q. What is the formula for finding the volume of a hemisphere?

Q. Define the term "composite shape" and give an example.

Q. How can you find the surface area of a composite shape?

Q. What is the formula for finding the volume of a hollow cylinder?

Q. How can you find the surface area of a hollow sphere?

Q. Explain the concept of "frustum of a cone."

Q. What is the formula for finding the total surface area of a cone frustum?

Q. How do you find the volume of a cone frustum?

Q. Define the term "triangular prism" and give an example of a real-life object that resembles it.

Q. How can you calculate the surface area of a triangular prism?

Q. How do you find the volume of a pentagonal prism?

Q. Define the term "polygonal pyramid" and give an example.

Q. What is the formula for finding the volume of a triangular pyramid?

Q. How can you calculate the surface area of a right circular cylinder?

Q. Define the term "net of a shape" and explain its significance.

Q. How do you find the surface area of an open cylinder?

Q. Define the term "tetrahedron" and give an example.

Q. What is the formula for finding the volume of a tetrahedron?

Q. Explain the concept of a "great circle" in a sphere.

Q. How do you calculate the area of a sector of a circle?

Q. Define the term "lateral area" and its significance.

Q. How can you find the total surface area of a solid hemisphere?

Q. What is the formula for finding the volume of a frustum of a pyramid?

Q. Explain the concept of "cuboid" and provide a real-life example.

Q. How do you calculate the total surface area of a cube?

Q. Define the terms "circular cone" and "right circular cone."

Q. How can you find the lateral surface area of a cone frustum?

Q. What is the formula for finding the total surface area of a rectangular prism?

Q. Explain the concept of a "diameter" and its relation to the radius of a circle.

Q. How can you find the volume of a frustum of a cone?

Chapter 14 Statistics

Q. What is the meaning of statistics?

Q. Name any two branches of statistics.

Q. Define mean in statistics.

Q. What is the mode of a data set?

Q. How is median calculated?

Q. Differentiate between range and mean.

Q. What is the purpose of constructing a frequency distribution table?

Q. How can you find the mode from a frequency distribution table?

Q. What is the range of a data set?

Q. Explain the concept of outliers in statistics.

Q. How is the range affected by outliers?

Q. What is the formula to find the mean of grouped data?

Q. Explain the concept of central tendency in statistics.

Q. How do you find the median for grouped data?

Q. Define cumulative frequency.

Q. Differentiate between discrete and continuous data.

Q. What is the importance of statistics in our daily lives?

Q. What is the difference between primary and secondary data?

Q. Define quartiles in statistics.

Q. Explain the concept of a box and whisker plot.

Q. How do you calculate the interquartile range?

Q. What is the difference between a sample and a population?

Q. Define the term 'random sample.'

Q. How do you calculate the mean absolute deviation?

Q. Explain the concept of probability in statistics.

Q. How is the probability of an event calculated?

Q. What is the difference between experimental and theoretical probability?

Q. Define correlation in statistics.

Q. How is the Pearson correlation coefficient calculated?

Q. Explain the concept of standard deviation.

Q. What does a high standard deviation indicate about a data set?

Q. Define the variance of a data set.

Q. How is the variance calculated?

Q. What is the significance of a normal distribution in statistics?

Q. Define the term 'z-score.'

Q. How do you find the z-score of a data point?

Q. What is the difference between a histogram and a bar graph?

Q. Define the term 'frequency polygon.'

Q. Explain the concept of a cumulative frequency curve.

Q. How do you find the median from an ogive graph?

Q. Define the term 'population mean.'

Q. How is the population mean denoted in statistics?

Q. What is the formula to calculate the population proportion?

Q. Explain the concept of standard error.

Q. How is standard error related to the sample size?

Q. Define the term 'random variable.'

Q. What is the difference between a discrete and a continuous random variable?

Q. Explain the concept of a probability distribution.

Q. How do you calculate the expected value of a random variable?

Q. Define the term 'statistical inference.'

Chapter 15 Probability

Q. What is probability?

Q. Define an experiment in the context of probability.

Q. What is an outcome?

Q. What is a sample space?

Q. State the basic principle of probability.

Q. What are equally likely outcomes?

Q. What is the probability of an event that is certain to happen?

Q. What is the probability of an event that is impossible to happen?

Q. How is probability calculated?

Q. What is the range of probability values?

Q. What does it mean if the probability of an event is 0?

Q. What does it mean if the probability of an event is 1?

Q. If all outcomes are equally likely, what is the probability of an event?

Q. If the probability of an event is 0.5, what does it mean?

Q. If we toss a fair coin, what is the probability of getting a head?

Q. If we roll a fair die, what is the probability of getting an odd number?

Q. What is the probability of drawing a red card from a well-shuffled deck of playing cards?

Q. If two unbiased coins are tossed together, what is the probability of getting at least one tail?

Q. What is the probability of selecting a vowel from the English alphabet?

Q. If two dice are rolled, what is the probability of obtaining a sum of 7?

Q. What is the probability of selecting a prime number from the digits 1 to 9?

Q. If a card is drawn from a pack of 52 cards, what is the probability of drawing a king or queen?

Q. If two cards are drawn from a pack of 52 cards without replacement, what is the probability of drawing two black cards?

Q. What is the probability of choosing a red pen from a bag containing 2 red pens and 5 blue pens?

Q. If a letter is chosen randomly from the word "MATHEMATICS," what is the probability that it is a vowel?

Q. A bag contains 3 red balls, 5 green balls, and 2 yellow balls. What is the probability of drawing a green ball?

Q. A box contains 10 chocolates, out of which 3 are mint-flavored. What is the probability of selecting a mint-flavored chocolate?

Q. What is the probability of selecting a card from a well-shuffled deck that is not a face card?

Q. If 2 dice are rolled, what is the probability of obtaining a sum less than 4?

Q. A bag contains 6 red balls and 4 blue balls. If one ball is drawn at random, what is the probability of drawing a red ball?

Q. If three coins are flipped, what is the probability of getting exactly two tails?

Q. What is the probability of rolling a number greater than 4 with a fair die?

Q. In a pack of 52 cards, what is the probability of drawing an ace of spades or a red card?

Q. A jar contains 4 red candies, 5 green candies, and 3 yellow candies. What is the probability of drawing a yellow candy?

Q. If two balls are drawn in succession without replacement from a bag containing 5 white balls and 3 black balls, what is the probability of drawing a white ball first and then a black ball?

Q. A box contains 15 apples, out of which 9 are sweet. What is the probability of selecting a sweet apple?

Q. What is the probability of obtaining at least one head when three fair coins are tossed?

Q. If a card is chosen randomly from a well-shuffled deck, what is the probability that it is a diamond?

Q. A jar contains 10 red marbles and 5 blue marbles. What is the probability of selecting a blue marble?

Q. If a die is rolled, what is the probability of rolling an even number?

Q. In a game, a die is rolled twice. What is the probability of getting a 5 in the first roll and a 2 in the second roll?

Q. What is the probability of flipping a fair coin and getting heads or tails?

Q. A bag contains 5 black balls, 3 red balls, and 2 green balls. What is the probability of drawing a black ball?

Q. If a card is drawn from a well-shuffled deck, what is the probability of drawing a face card?

Q. In a box containing 15 pens, 4 are blue, and the rest are black. What is the probability of selecting a black pen?

Q. If a card is chosen from a deck of cards, what is the probability of selecting a club or a spade?

Q. In a basket, there are 4 red apples, 6 green apples, and 5 yellow apples. What is the probability of selecting a red apple?

Q. If two dice are rolled, what is the probability of getting an even number on both dice?

Q. What is the probability of getting tails if a fair coin is tossed?

Q. A bag contains 8 white balls and 4 red balls. If one ball is drawn at random, what is the probability of drawing a red ball?