Write the numeral form of five thousand seven hundred eight.
Do it yourself
Which is the smallest three-digit number?
Do it yourself
What are the multiples of 5 between 20 and 50?
Do it yourself
Write the Roman numeral for 1000.
Do it yourself
What is the face value of 9 in the number 729?
Do it yourself
Which is the greatest three-digit odd number?
Do it yourself
What is the sum of the smallest three-digit number and the greatest two-digit number?
Do it yourself
Write the numeral form of two lakh forty thousand five.
Do it yourself
What is the value of (9 × 100) + (9 × 10) + 9?
Do it yourself
Which is the smallest prime number?
Do it yourself
How many factors does the number 12 have?
Do it yourself
What is the product of 12 and its successor?
Do it yourself
Write the numeral form of one crore.
Do it yourself
What is the remainder when 235 is divided by 7?
Do it yourself
Identify the even numbers between 30 and 40.
Do it yourself
What is the sum of the first five prime numbers?
Do it yourself
Which is the nearest whole number to 25.876?
Do it yourself
What is 75% of 200?
Do it yourself
Write the smallest four-digit number using the digits 1, 3, 5, and 7 without repetition.
Do it yourself
What is the value of 10^3?
Do it yourself
What is the sum of the first ten multiples of 6?
Do it yourself
How many hundreds are there in five lakhs?
Do it yourself
Find the average of 28, 32, and 35.
Do it yourself
Convert 5/8 into a decimal.
Do it yourself
Find the value of (8 × 10) - (4 × 5).
Do it yourself
What is the unit's digit in the square of 9?
Do it yourself
Simplify: 5 × 7 + 4 - 18 ÷ 3.
Do it yourself
What is the sum of the first 20 natural numbers?
Do it yourself
What is the place value of 2 in the number 786.42?
Do it yourself
Subtract 0.24 from 1.75.
Do it yourself
Find the number using the clues: It is greater than 37 but less than 45. It is divisible by 5 and 6.
Do it yourself
What is the sum of all the factors of 24?
Do it yourself
Identify the odd numbers between 50 and 60.
Do it yourself
89 days is equal to how many weeks and days?
Do it yourself
Express the number 21/50 as a percentage.
Do it yourself
A shopkeeper bought a watch for $400 and sold it for $480. What was the profit percentage?
Do it yourself
What is the value of (3/4) ÷ (1/5)?
Do it yourself
Multiply 3/5 by 25.
What is the sum of 2/3 and 1/6?
Do it yourself
Express the fraction 7/8 as a decimal.
Do it yourself
If a number is divisible by 9, then what other number will also divide it?
Do it yourself
What is the product of (-6) and 9?
The perimeter of a square is 40 cm. Find its side length.
Do it yourself
If a number ends with zero, then what will be its digit in the unit's place after multiplying by
any number?
Do it yourself
What is the value of (4 + 6) × 3 - 8?
Answer Youself
Chapter 2 Whole Numbers
What is the smallest whole number?
Do it yourself
Write the next three whole numbers after 5.
Do it yourself
Identify the place value of the digit 8 in the number 874.
Do it yourself
What is the successor of 100?
Do it yourself
Give the predecessor of 65.
Do it yourself
Which is the largest two-digit number?
Do it yourself
What is the sum of 25 and 10?
Do it yourself
Perform the subtraction: 128 - 47.
Do it yourself
If a number ends with zero, is it always divisible by 10?
Do it yourself
Multiply 15 by 6.
Do it yourself
Divide 80 by 8.
Do it yourself
What is the smallest prime number?
Do it yourself
Write the expanded form of the number 462.
Do it yourself
What is the value of the digit 2 in the number 924?
Do it yourself
Find the product of 9 and 7.
Do it yourself
What is the quotient of 49 divided by 7?
Do it yourself
Simplify: 8 - 6 + 5 - 3.
Do it yourself
Write 10,000 in words.
Do it yourself
What is the successor of 999?
Do it yourself
Determine the square of 5.
Do it yourself
Identify the sum of the place values of the digit 3 in 356.
Do it yourself
If a number starts with zero, is it always less than 100?
Do it yourself
Multiply 13 by 2.
Do it yourself
Divide 48 by 6.
Do it yourself
What is the largest composite number?
Do it yourself
Write the expanded form of 805.
Do it yourself
What is the value of the digit 1 in the number 761?
Do it yourself
Find the product of 11 and 8.
Do it yourself
What is the quotient of 63 divided by 9?
Do it yourself
Simplify: 9 - 4 + 6 - 2.
Do it yourself
Write 100,000 in words.
Do it yourself
Determine the square of 9.
Do it yourself
Identify the sum of the place values of the digit 7 in 971.
Do it yourself
Multiply 16 by 3.
Do it yourself
Divide 54 by 6.
Do it yourself
What is the smallest composite number?
Do it yourself
Write the expanded form of 245.
Do it yourself
What is the value of the digit 6 in the number 864?
Do it yourself
Find the product of 12 and 7.
Do it yourself
What is the quotient of 72 divided by 9?
Do it yourself
Simplify: 7 - 2 + 3 - 1.
Do it yourself
Write 1,000,000 in words.
Do it yourself
Determine the square of 2.
Do it yourself
Identify the sum of the place values of the digit 9 in 598.
Do it yourself
Multiply 14 by 5.
Do it yourself
Divide 63 by 9.
Do it yourself
What is the smallest positive whole number?
Do it yourself
Write the expanded form of 890.
Do it yourself
What is the value of the digit 3 in the number 739?
Do it yourself
Find the product of 9 and 9.
Do it yourself
Chapter 3 Playing with Numbers
What is the smallest prime number?
Do It Yourself
Is 1 a prime number? Why or why not?
Do It Yourself
List the first five prime numbers.
Do It Yourself
How many prime numbers are there between 10 and 20?
Do It Yourself
What is a composite number?
Do It Yourself
Is 15 a prime or a composite number?
Do It Yourself
What is the greatest common factor (GCF) of 8 and 12?
Do It Yourself
Find the LCM (Least Common Multiple) of 4 and 6.
Do It Yourself
Is 1 a factor of every number?
Do It Yourself
Is 0 a factor of any number? Why or why not?
Do It Yourself
How can you test whether a number is divisible by 2?
Do It Yourself
How can you test whether a number is divisible by 3?
Do It Yourself
What are the prime factors of 24?
Do It Yourself
Find the LCM of 3, 5, and 7.
Do It Yourself
Determine the HCF of 16 and 24.
Do It Yourself
What is the unit digit of any number that is divisible by 10?
Do It Yourself
Find the sum of the digits of the number 123.
Do It Yourself
How can you check if a number is divisible by 9?
Do It Yourself
What is a factor pair of a number?
Do It Yourself
Find the prime factorization of 45.
Do It Yourself
What is the sum of the prime factors of 48?
Do It Yourself
Find the LCM and HCF of 36 and 48.
Do It Yourself
If a number has an even number of prime factors, is the number a perfect square? Why or why not?
Do It Yourself
How can you check if a number is divisible by 4?
Do It Yourself
Is every even number a multiple of 2? Why or why not?
Do It Yourself
What are odd numbers?
Do It Yourself
Can the sum of two odd numbers be an even number?
Do It Yourself
If an odd number is subtracted from an even number, what type of number will the result be?
Do It Yourself
What is the prime factorization of 36?
Do It Yourself
Find the LCM of 8, 12, and 16.
Do It Yourself
What is the sum of the digits of a number divisible by 3?
Do It Yourself
Can the sum of the digits of a number ever be 9 if the number is even? Why or why not?
Do It Yourself
How can you test if a number is divisible by 5?
Do It Yourself
Are all multiples of 5 ending in 5 or 0? Why or why not?
Do It Yourself
Find the LCM and HCF of 18 and 24.
Do It Yourself
Determine if 57 is divisible by 9.
Do It Yourself
What is the HCF of 15 and 25?
Do It Yourself
What is a multiple of a number?
Do It Yourself
Determine the prime factors of 64.
Do It Yourself
Find the LCM of 10, 15, and 20.
Do It Yourself
How can you test whether a number is divisible by 6?
Do It Yourself
What is the unit digit of any even number?
Do It Yourself
Determine the HCF of 28 and 42.
Do It Yourself
Can a number be a multiple of both 2 and 3? Provide an example.
Do It Yourself
Find the LCM and HCF of 50 and 75.
Do It Yourself
What is the term used for both the LCM and HCF of two numbers?
Do It Yourself
How many prime numbers are there between 20 and 30?
Do It Yourself
What is the sum of the first three prime numbers?
Do It Yourself
Find the prime factorization of 72.
Do It Yourself
Determine the LCM and HCF of 14 and 21.
Do It Yourself
Chapter 4 Basic Geometrical Ideas
What is geometry?
Do It Yourself
Define a line segment.
Do It Yourself
What is the difference between a line segment and a line?
Do It Yourself
Name the different types of angles.
Do It Yourself
What is the sum of angles in a triangle?
Do It Yourself
Define a right angle.
Do It Yourself
What is the difference between a right angle and an acute angle?
Do It Yourself
Name the different types of triangles based on their sides.
Do It Yourself
Name the different types of triangles based on their angles.
Do It Yourself
Define a quadrilateral.
Do It Yourself
Name the different types of quadrilaterals.
Do It Yourself
How many sides does a hexagon have?
Do It Yourself
What is the difference between a square and a rectangle?
Do It Yourself
Define a circle.
Do It Yourself
What is the radius of a circle?
Do It Yourself
What is the diameter of a circle?
Do It Yourself
Name the parts of a circle.
Do It Yourself
What is the difference between a line of symmetry and a rotational symmetry?
Do It Yourself
How many lines of symmetry does a rectangle have?
Do It Yourself
Define parallel lines.
Do It Yourself
What is the difference between parallel lines and perpendicular lines?
Do It Yourself
Name a pair of intersecting lines.
Do It Yourself
What is the sum of angles in a straight line?
Do It Yourself
Define a regular polygon.
Do It Yourself
Name a regular polygon with six sides.
Do It Yourself
How many symmetry axes does a regular pentagon have?
Do It Yourself
Name a pair of adjacent angles.
Do It Yourself
Define an isosceles triangle.
Do It Yourself
What is the difference between a scalene triangle and an equilateral triangle?
Do It Yourself
Name a polygon with eight sides.
Do It Yourself
What is the perimeter of a rectangle with sides measuring 4 cm and 5 cm?
Do It Yourself
Define a pentagon.
Do It Yourself
How many vertices does an octagon have?
Do It Yourself
Name a pair of alternate angles.
Do It Yourself
What is the difference between a trapezium and a parallelogram?
Do It Yourself
Define a tangent to a circle.
Do It Yourself
How many diagonals does a hexagon have?
Do It Yourself
Define a sector of a circle.
Do It Yourself
Name a pair of vertically opposite angles.
Do It Yourself
What is the sum of angles in a quadrilateral?
Do It Yourself
Define a line of symmetry.
Do It Yourself
How many right angles are there in a rectangle?
Do It Yourself
Name a pair of corresponding angles.
Do It Yourself
What is the difference between concentric and non-concentric circles?
Do It Yourself
Define an obtuse angle.
Do It Yourself
Name a regular polygon with four sides.
Do It Yourself
How many lines of symmetry does an equilateral triangle have?
Do It Yourself
Define a semi-circle.
Do It Yourself
What is the sum of angles in a polygon with eight sides?
Do It Yourself
Name a pair of supplementary angles.
Do It Yourself
Chapter 5 Understanding Elementary Shapes
What is a point in geometry?
Do It Yourself
Define a line segment.
Do It Yourself
Describe a ray.
Do It Yourself
How is an angle formed?
Do It Yourself
What are parallel lines?
Do It Yourself
Explain the concept of perpendicular lines.
Do It Yourself
What is a right angle?
Do It Yourself
Define an acute angle.
Do It Yourself
Describe an obtuse angle.
Do It Yourself
How do we measure the size of an angle?
Do It Yourself
What is a triangle?
Do It Yourself
How many sides does a quadrilateral have?
Do It Yourself
Define a polygon.
Do It Yourself
What is a circle?
Do It Yourself
How is the radius of a circle different from its diameter?
Do It Yourself
Explain the concept of symmetry.
Do It Yourself
What are congruent shapes?
Do It Yourself
Name two types of regular polygons.
Do It Yourself
How many edges does a cube have?
Do It Yourself
What is the difference between an open and a closed curve?
Do It Yourself
Describe the properties of a rectangle.
Do It Yourself
What is the difference between a square and a rhombus?
Do It Yourself
Explain the concept of a line of symmetry.
Do It Yourself
How many sides does a hexagon have?
Do It Yourself
Describe the properties of a parallelogram.
Do It Yourself
What are acute, obtuse, and right-angled triangles?
Do It Yourself
How is the area of a rectangle calculated?
Do It Yourself
Define the perimeter of a shape.
Do It Yourself
Explain the concept of congruency.
Do It Yourself
What is the sum of the interior angles of a triangle?
Do It Yourself
Describe the properties of a trapezium.
Do It Yourself
Define the term "diagonal" in a polygon.
Do It Yourself
How is the area of a square calculated?
Do It Yourself
What is a regular polygon?
Do It Yourself
How many sides does a pentagon have?
Do It Yourself
Define a line of symmetry in a shape.
Do It Yourself
Explain the concept of rotational symmetry.
Do It Yourself
What is the difference between a scalene and an isosceles triangle?
Do It Yourself
How is the area of a circle calculated?
Do It Yourself
Define the term "chord" in a circle.
Do It Yourself
Describe the properties of a kite.
Do It Yourself
How do we classify shapes based on their sides and angles?
Do It Yourself
Explain the concept of congruent triangles.
Do It Yourself
What is the formula for the perimeter of a rectangle?
Do It Yourself
Define the term "vertex" in geometry.
Do It Yourself
How is the area of a triangle calculated?
Do It Yourself
Describe the properties of a regular hexagon.
Do It Yourself
What is the difference between a convex and a concave shape?
Do It Yourself
How many sides does an octagon have?
Do It Yourself
Define the term "circumference" in a circle.
Do It Yourself
Chapter 6 Integers
What is an integer?
Do it yourself
Give an example of a positive integer.
Do it yourself
Give an example of a negative integer.
Do it yourself
What is the opposite of an integer?
Do it yourself
State the rule for adding two positive integers.
Do it yourself
State the rule for adding two negative integers.
Do it yourself
State the rule for adding a positive and a negative integer.
Do it yourself
What is the result when you add a number and its opposite?
Do it yourself
What is the result when you subtract an integer from itself?
Do it yourself
What is the result when you multiply two positive integers?
Do it yourself
What is the result when you multiply a positive and a negative integer?
Do it yourself
What happens if you multiply any number by zero?
Do it yourself
State the rule for dividing two positive integers.
Do it yourself
State the rule for dividing two negative integers.
Do it yourself
State the rule for dividing a positive and a negative integer.
Do it yourself
What is the result when you divide zero by any number?
Do it yourself
What is the result when you divide any number by zero?
Do it yourself
What is the result when you add a positive integer and zero?
Do it yourself
What is the result when you add a negative integer and zero?
Do it yourself
What is the result when you subtract zero from any number?
Do it yourself
What is the result when you subtract an integer from zero?
Do it yourself
State the rule for multiplying any number by one.
Do it yourself
State the rule for dividing any number by one.
Do it yourself
What is the absolute value of an integer?
Do it yourself
What is the sum of the absolute values of -3 and 7?
Do it yourself
What is the product of the absolute values of -4 and -2?
Do it yourself
What happens when you add zero to an integer?
Do it yourself
What happens when you subtract zero from an integer?
Do it yourself
What happens when you multiply a number by zero?
Do it yourself
What is the result when you divide zero by any non-zero number?
Do it yourself
What is the result when you divide a non-zero number by zero?
Do it yourself
What is the result when you divide a number by one?
Do it yourself
What is the result when you multiply any number by negative one?
Do it yourself
What is the result when you divide any number by negative one?
Do it yourself
What is the result when you add two odd integers?
Do it yourself
What is the result when you add two even integers?
Do it yourself
What is the result when you subtract an even integer from an odd integer?
Do it yourself
What is the result when you subtract an odd integer from an even integer?
Do it yourself
What is the sum of two consecutive integers?
Do it yourself
What is the product of two consecutive integers?
Do it yourself
What is the sum of three consecutive integers?
Do it yourself
What is the product of three consecutive integers?
Do it yourself
What is the result when you multiply an odd integer by an even integer?
Do it yourself
What happens when you divide an odd integer by an even integer?
Do it yourself
What is the result when you multiply two odd integers?
Do it yourself
What is the result when you multiply two even integers?
Do it yourself
What is the result when you multiply an odd integer by zero?
Do it yourself
What is the result when you multiply an even integer by zero?
Do it yourself
What is the result when you raise any number to the power of zero?
Do it yourself
What is the result when you raise zero to any non-zero power?
Do it yourself
Chapter 7 Fractions
What is a fraction?
Do it yourself
Define numerator and denominator of a fraction.
Do it yourself
Give an example of a fraction.
Do it yourself
Write the fraction represented by the shaded part below:
Do it yourself
Convert 3/5 into a mixed number.
Do it yourself
Convert 9/4 into a mixed number.
Do it yourself
Write the fraction equivalent to 0.75.
Do it yourself
Expand 1/3 as a decimal.
Do it yourself
Simplify 12/18 to its lowest terms.
Do it yourself
Simplify 25/100 to its simplest form.
Do it yourself
Add 1/4 and 2/5.
Do it yourself
Subtract 3/8 from 5/8.
Do it yourself
Multiply 2/3 by 4/5.
Do it yourself
Divide 3/4 by 2/3.
Do it yourself
Simplify (2/5) ÷ (1/2).
Do it yourself
Find a fraction that lies between 1/3 and 1/2.
Do it yourself
Arrange the following fractions in ascending order: 1/8, 3/10, 2/5.
Do it yourself
Arrange the following fractions in descending order: 5/6, 3/4, 7/12.
Do it yourself
What fraction is larger: 5/6 or 3/5?
Do it yourself
What fraction is smaller: 2/7 or 1/4?
Do it yourself
Express 75% as a fraction.
Do it yourself
Express 5/8 as a percentage.
Do it yourself
Find the fraction that represents the shaded part below:
Do it yourself
Convert 3/4 into a decimal.
Do it yourself
Convert 0.6 into a fraction.
Do it yourself
Multiply 1/3 by 3.
Do it yourself
Multiply 5/8 by 2/3.
Do it yourself
Simplify (3/4) x (2/5).
Do it yourself
Simplify (2/3) ÷ (4/5).
Do it yourself
Add 5/6 and 2/9.
Do it yourself
Subtract 4/5 from 1.
Do it yourself
Change 4/7 into an equivalent fraction with a denominator of 28.
Do it yourself
Change 3/4 into an equivalent fraction with a denominator of 32.
Do it yourself
Find the value of x: 3/5 = x/10.
Do it yourself
Find the value of y: y/6 = 2/3.
Do it yourself
Divide 5/6 by 2/3.
Do it yourself
Find 3 consecutive fractions whose sum is 1.
Do it yourself
Find a fraction smaller than 3/4 and larger than 1/2.
Do it yourself
Solve the equation: x/4 = 1/8.
Do it yourself
Solve the equation: y/5 = 3/10.
Do it yourself
Express 2.5 as a fraction in the simplest form.
Do it yourself
A recipe calls for 3/4 cup of flour and 1/2 cup of sugar. How much flour and sugar do you need in
total?
Do it yourself
In a class, 2/5 of the students are boys. If there are 30 students in total, how many of them are
boys?
Do it yourself
A tank is filled with 5/8 of its capacity. If the capacity of the tank is 80 liters, how much water
is in the tank?
Do it yourself
John spent 3/4 of his pocket money on a toy. If he had $20 in total, how much did he spend on the
toy?
Do it yourself
Sally solved 1/3 of her math problems on Monday and 3/5 on Tuesday. What fraction of the problems
is
left to solve?
Do it yourself
Express 2/3 as a decimal.
Do it yourself
Express 0.9 as a fraction in simplest form.
Do it yourself
Add 1/5, 2/3, and 3/4.
Do it yourself
Subtract 4/5 from 1/2.
Do it yourself
Chapter 8 Decimals
What is a decimal number?
Do it yourself
How is a decimal number different from a whole number?
Do it yourself
What is the place value of the first digit after the decimal point?
Do it yourself
How can you write a decimal number in words?
Do it yourself
What is the value of the digit 6 in the number 0.624?
Do it yourself
How can you compare two decimal numbers?
Do it yourself
What is the meaning of the term "tenths" in decimals?
Do it yourself
How can you convert a fraction into a decimal?
Do it yourself
How can you convert a decimal into a fraction?
Do it yourself
What is the decimal representation of 1/2?
Do it yourself
How can you round off a decimal number to the nearest whole number?
Do it yourself
What happens when you multiply a decimal number by 10?
Do it yourself
How can you multiply a decimal by a whole number?
Do it yourself
How can you divide a decimal by a whole number?
Do it yourself
How can you find the missing value in a calculation involving decimals?
Do it yourself
What is the meaning of the term "hundredths" in decimals?
Do it yourself
How can you write a decimal number as a percent?
Do it yourself
How can you order three decimal numbers from smallest to largest?
Do it yourself
How can you add two decimal numbers together?
Do it yourself
How can you subtract a decimal number from another decimal number?
Do it yourself
How can you multiply two decimal numbers together?
Do it yourself
How can you divide a decimal number by another decimal number?
Do it yourself
How can you find the average of a set of decimal numbers?
Do it yourself
How can you solve a word problem involving decimals?
Do it yourself
How can you convert a decimal number into a mixed number or a whole number with a fraction?
Do it yourself
How can you convert a fraction into a decimal without using a calculator?
Do it yourself
How can you convert a repeating decimal into a fraction?
Do it yourself
What is the place value of the second digit after the decimal point?
Do it yourself
How can you change a decimal into a percentage?
Do it yourself
How can you change a percentage into a decimal?
Do it yourself
How can you change a decimal into a fraction in simplest form?
Do it yourself
What is the meaning of the term "thousandths" in decimals?
Do it yourself
How can you convert a decimal into a fraction with a power of 10 in the denominator?
Do it yourself
How can you rewrite a fraction with a denominator of 10, 100, or 1000 as a decimal?
Do it yourself
How can you compare three decimal numbers using greater than and less than symbols?
Do it yourself
How can you express a decimal as a sum of fractions?
Do it yourself
How can you multiply a decimal number by 100?
Do it yourself
How can you divide a decimal number by 1000?
Do it yourself
How can you round off a decimal number to a specific decimal place?
Do it yourself
How can you express a decimal as a ratio of two integers?
Do it yourself
How can you multiply a decimal by a power of ten?
Do it yourself
How can you divide a decimal by a power of ten?
Do it yourself
How can you add or subtract decimals with different place values?
Do it yourself
How can you estimate the product of two decimal numbers?
Do it yourself
How can you estimate the quotient of two decimal numbers?
Do it yourself
How can you solve a decimal word problem involving money?
Do it yourself
How can you find a fraction equivalent to a given decimal?
Do it yourself
How can you convert a repeating decimal into a percent?
Do it yourself
How can you convert a decimal number into an improper fraction?
Do it yourself
How can you determine the number of digits after the decimal point in a decimal number?
Do it yourself
Chapter 9 Data Handling
What is data?
Do it yourself
Give an example of qualitative data.
Do it yourself
Give an example of quantitative data.
Do it yourself
What is the difference between a bar graph and a pictograph?
Do it yourself
Define frequency in terms of data handling.
Do it yourself
What is the mode of the data set: 2, 4, 4, 6, 8?
Do it yourself
Arrange the following data in ascending order: 5, 12, 1, 9, 3.
Do it yourself
What is the median of the data set: 4, 8, 10, 12, 14?
Do it yourself
Create a bar graph to represent the number of students in each grade (1-5).
Do it yourself
What is the range of the data set: 6, 9, 11, 15, 18?
Do it yourself
What is the mode of the data set: 3, 3, 7, 7, 7?
Do it yourself
What is the median of the data set: 4, 6, 8, 12, 19?
Do it yourself
In a survey, 12 students voted for their favorite sport. Represent this data using a pictograph.
Do it yourself
Define the term 'outlier' in data handling.
Do it yourself
What are the different types of graphs used for data representation?
Do it yourself
Define the term 'frequency table.'
Do it yourself
Calculate the mean of the data set: 3, 7, 9, 12, 15.
Do it yourself
What is the mode of the data set: 5, 8, 8, 10, 12?
Do it yourself
Create a line graph to represent the temperature changes throughout a week.
Do it yourself
What is the range of the data set: 4, 6, 9, 13, 19?
Do it yourself
What is the median of the data set: 2, 8, 9, 9, 13?
Do it yourself
How many modes does the data set 4, 5, 5, 6, 8 have?
Do it yourself
What is the mean of the data set: 2, 4, 6, 8, 10?
Do it yourself
Create a bar graph to represent the number of books read by each student in a class.
Do it yourself
Define the term 'data set.'
Do it yourself
Explain the concept of class intervals in data handling.
Do it yourself
Calculate the mode of the data set: 2, 3, 5, 5, 7.
Do it yourself
What is the median of the data set: 6, 7, 9, 9, 20?
Do it yourself
Create a line graph to represent the population growth in a town over 10 years.
Do it yourself
What is the range of the data set: 7, 8, 10, 14, 15?
Do it yourself
How many modes does the data set 2, 3, 4, 4, 5 have?
Do it yourself
What is the mean of the data set: 5, 6, 8, 12, 16?
Do it yourself
Create a bar graph to represent the number of cars produced by different companies.
Do it yourself
What is the mode of the data set: 3, 5, 7, 7, 7, 9?
Do it yourself
What is the median of the data set: 3, 6, 8, 8, 9?
Do it yourself
Calculate the mean of the data set: 4, 6, 9, 12, 15.
Do it yourself
Define the term 'line plot' in data handling.
Do it yourself
What is the mode of the data set: 2, 4, 6, 6, 8, 8, 10?
Do it yourself
Create a line graph to represent the quarterly sales of a company.
Do it yourself
Calculate the range of the data set: 5, 7, 8, 10, 13.
Do it yourself
What is the median of the data set: 4, 4, 5, 8, 9?
Do it yourself
How many modes does the data set 1, 3, 5, 5, 7 have?
Do it yourself
What is the mean of the data set: 2, 3, 5, 6, 8?
Do it yourself
Create a bar graph to represent the number of fruits of different types in a basket.
Do it yourself
Define the term 'survey' in data handling.
Do it yourself
What is the range of the data set: 3, 6, 8, 10, 14?
Do it yourself
What is the mode of the data set: 2, 4, 4, 4, 6?
Do it yourself
Calculate the median of the data set: 7, 8, 9, 10, 18.
Do it yourself
Create a line graph to represent the stock prices of a company over a month.
Do it yourself
Explain the concept of the mean, median, and mode in data handling.
Do it yourself
Chapter 10 Mensuration
What is the meaning of mensuration?
Do it yourself
Define perimeter.
Do it yourself
How is the perimeter of a rectangle calculated?
Do it yourself
What is the formula for the perimeter of a square?
Do it yourself
Define area.
Do it yourself
How is the area of a rectangle calculated?
Do it yourself
What is the formula for the area of a square?
Do it yourself
Calculate the perimeter of a rectangle with length 6 cm and width 4 cm.
Do it yourself
Find the area of a rectangle with length 8 m and width 5 m.
Do it yourself
Calculate the perimeter of a square with side length 3 cm.
Do it yourself
Find the area of a square with side length 5 m.
Do it yourself
Define circumference.
Do it yourself
How is the circumference of a circle calculated?
Do it yourself
Calculate the circumference of a circle with radius 4 cm.
Do it yourself
Define radius.
Do it yourself
Calculate the radius of a circle with a circumference of 30 cm.
Do it yourself
What is the formula for the area of a circle?
Do it yourself
Find the area of a circle with a radius of 5 cm.
Do it yourself
Define diameter.
Do it yourself
How is the diameter of a circle related to its radius?
Do it yourself
Calculate the diameter of a circle with a radius of 6 cm.
Do it yourself
What is the formula for the perimeter of a triangle?
Do it yourself
Calculate the perimeter of a triangle with sides measuring 3 cm, 4 cm, and 5 cm.
Do it yourself
Define base and height in a triangle.
Do it yourself
How is the area of a triangle calculated?
Do it yourself
Find the area of a triangle with a base of 6 cm and height of 8 cm.
Do it yourself
Define square units.
Do it yourself
How are square units used in measuring area?
Do it yourself
Calculate the area of a rectangle with measurements 7 cm by 9 cm, in square units.
Do it yourself
Define cubic units.
Do it yourself
How are cubic units used in measuring volume?
Do it yourself
Calculate the volume of a rectangular prism with length 4 cm, width 3 cm, and height 5 cm.
Do it yourself
Define volume.
Do it yourself
How is the volume of a cube calculated?
Do it yourself
Calculate the volume of a cube with side length 2 cm.
Do it yourself
Define face, edge, and vertex in a solid shape.
Do it yourself
What is the difference between a rectangular prism and a cube?
Do it yourself
Calculate the surface area of a rectangular prism with length 6 cm, width 4 cm, and height 3 cm.
Do it yourself
Define lateral area.
Do it yourself
How is the lateral area of a cylinder calculated?
Do it yourself
Calculate the lateral area of a cylinder with a radius of 2 cm and height of 5 cm.
Do it yourself
Define total surface area.
Do it yourself
How is the total surface area of a cube calculated?
Do it yourself
Calculate the total surface area of a cube with side length 3 cm.
Do it yourself
Define diagonal.
Do it yourself
How is the diagonal of a rectangular prism calculated?
Do it yourself
Calculate the diagonal of a rectangular prism with length 5 cm, width 4 cm, and height 3 cm.
Do it yourself
Define congruent shapes.
Do it yourself
How can you determine if two shapes are congruent?
Do it yourself
Calculate the area of a triangle with a base of 10 cm and height of 6 cm.
Do it yourself
Chapter 11 Algebra
What is algebra?
Do it yourself
Define variables and constants in algebra.
Do it yourself
What is an algebraic expression?
Do it yourself
How can you differentiate between an equation and an expression in algebra?
Do it yourself
Simplify the following expression: 3x + 2y - x + 4y.
Do it yourself
Express the phrase "three more than a number" as an algebraic expression.
Do it yourself
Solve the equation: 5x - 3 = 12.
Do it yourself
If x = 3, evaluate the expression 2x + 5.
Do it yourself
Write the additive inverse of the number -7.
Do it yourself
What is the coefficient of x in the expression 4x + 2?
Do it yourself
Simplify: 2(x + 3) - 4.
Do it yourself
What is the result of multiplying -5 by -4?
Do it yourself
Solve the equation: 2x = 10.
Do it yourself
Evaluate the expression 3y - 2y + 7 when y = 5.
Do it yourself
What is the product of -8 and -7?
Do it yourself
Simplify: 2(x - 4) + 3(x + 2).
Do it yourself
Solve the equation: 3(x - 2) = 15.
Do it yourself
If x = 4, find the value of 2x^2 - 5x + 3.
Do it yourself
What happens when you multiply a number by 0?
Do it yourself
Solve the equation: 4(x + 5) = 36.
Do it yourself
Evaluate the expression 2z^2 - 3z + 4 when z = -2.
Do it yourself
Write the opposite of the number 9.
Do it yourself
Simplify: 6(x + 2) - 3(2x + 4).
Do it yourself
What is the solution to the equation 3x - 2 = 7?
Do it yourself
If y = 2, find the value of 3y^2 - 2y + 1.
Do it yourself
Express the phrase "the sum of a and b" as an algebraic expression.
Do it yourself
Evaluate the expression 5x - 3y when x = 2 and y = 4.
Do it yourself
Solve the equation: 2(x + 1) + 3x = 10.
Do it yourself
Simplify: 4x - 2(3x - 1).
Do it yourself
What is the value of x in the equation x/4 = 3?
Do it yourself
If a = -2 and b = 5, evaluate the expression ab + a^2.
Do it yourself
Write the additive inverse of -12.
Do it yourself
Simplify: (2x + 3) - (5x - 2).
Do it yourself
Solve the equation: 4x + 7 = 15.
Do it yourself
If x = 3, find the value of 2x^3 - 3x^2 + 4x - 1.
Do it yourself
Express the phrase "the difference between x and y" as an algebraic expression.
Do it yourself
Evaluate the expression 2a^2 - 3a + 1 when a = -1.
Do it yourself
Solve the equation: 3(2x - 1) = 21.
Do it yourself
Simplify: 3(x + 4) - (2x + 5).
Do it yourself
What is the value of y in the equation 5y/2 = 10?
Do it yourself
If x = -3, find the value of x^2 - 2x - 3.
Do it yourself
Write the opposite of the number -8.
Do it yourself
Simplify: (4x - 6) + (2 - 5x).
Do it yourself
Solve the equation: 6 - 4x = 2x + 8.
Do it yourself
If x = 2, evaluate the expression 3x^2 - 2x + 5.
Do it yourself
Express the phrase "twice a number" as an algebraic expression.
Do it yourself
Evaluate the expression 3a - 2b when a = 4 and b = -3.
Do it yourself
Solve the equation: 3(x - 5) = 9.
Do it yourself
If x = 1, find the value of 2x^2 - 3x + 1.
Do it yourself
Write the additive inverse of 0.
Do it yourself
Chapter 12 Ratio and Proportion
What is a ratio?
Do it yourself
Define proportion in simple terms.
Do it yourself
How can you express a ratio?
Do it yourself
What is the difference between a ratio and a fraction?
Do it yourself
Explain the concept of equivalent ratios.
Do it yourself
How can you simplify a ratio?
Do it yourself
What is meant by the term "ratio in simplest form"?
Do it yourself
What is the difference between a direct ratio and an inverse ratio?
Do it yourself
How can you find the missing term in a proportion?
Do it yourself
If the ratio of boys to girls in a class is 3:5, and there are 24 girls, how many boys are there?
Do it yourself
If 2 pens cost $5, how much will 5 pens cost?
Do it yourself
A recipe requires 2 cups of flour and 3 cups of sugar. If you want to make half the recipe, how
much
flour do you need?
Do it yourself
If a car travels a distance of 240 km in 4 hours, what is its speed?
Do it yourself
If it takes 3 hours to paint a room, how much time will it take to paint 2 rooms?
Do it yourself
A map scale is 1 inch equals 10 miles. How far apart are two cities if they are 2.5 inches apart on
the map?
Do it yourself
If a rectangle has a length of 15 cm and a width of 10 cm, what is its aspect ratio?
Do it yourself
The ratio of students to teachers in a school is 25:3. If there are 225 students, how many teachers
are there?
Do it yourself
In a bag of marbles, the ratio of red to blue marbles is 2:5. If there are 28 blue marbles, how
many
red marbles are there?
Do it yourself
A train covers a distance of 420 km in 6 hours. What is its average speed?
Do it yourself
If the ratio of flour to sugar in a cake recipe is 3:2, and you need 2 cups of sugar, how much
flour
do you need?
Do it yourself
The ratio of boys to girls in a class is 2:3. If there are 25 girls, how many boys are there?
Do it yourself
If 5 pens cost $10, how much will 7 pens cost?
Do it yourself
A recipe requires 4 cups of flour and 2 cups of sugar. If you want to make one-fourth of the
recipe,
how much sugar do you need?
Do it yourself
If a car travels a distance of 180 km in 3 hours, what is its speed?
Do it yourself
If it takes 2 hours to paint a room, how much time will it take to paint 4 rooms?
Do it yourself
A map scale is 1 inch equals 20 miles. How far apart are two cities if they are 3 inches apart on
the map?
Do it yourself
If a rectangle has a length of 25 cm and a width of 15 cm, what is its aspect ratio?
Do it yourself
The ratio of students to teachers in a school is 30:5. If there are 150 students, how many teachers
are there?
Do it yourself
In a bag of marbles, the ratio of red to blue marbles is 3:7. If there are 42 blue marbles, how
many
red marbles are there?
Do it yourself
A train covers a distance of 300 km in 4 hours. What is its average speed?
Do it yourself
31. If the ratio of flour to sugar in a cake recipe is 2:3, and you need 5 cups of sugar, how much flour
do you need?
Do it yourself
The ratio of boys to girls in a class is 1:4. If there are 20 girls, how many boys are there?
Do it yourself
If 3 pens cost $6, how much will 9 pens cost?
Do it yourself
A recipe requires 3 cups of flour and 1 cup of sugar. If you want to make one-half of the recipe,
how much sugar do you need?
Do it yourself
If a car travels a distance of 120 km in 2 hours, what is its speed?
Do it yourself
If it takes 4 hours to paint a room, how much time will it take to paint 3 rooms?
Do it yourself
A map scale is 1 inch equals 30 miles. How far apart are two cities if they are 4.5 inches apart on
the map?
Do it yourself
If a rectangle has a length of 30 cm and a width of 20 cm, what is its aspect ratio?
Do it yourself
The ratio of students to teachers in a school is 20:4. If there are 100 students, how many teachers
are there?
Do it yourself
In a bag of marbles, the ratio of red to blue marbles is 4:9. If there are 63 blue marbles, how many
red marbles are there?
Do it yourself
A train covers a distance of 240 km in 3 hours. What is its average speed?
Do it yourself
If the ratio of flour to sugar in a cake recipe is 4:5, and you need 8 cups of sugar, how much flour
do you need?
Do it yourself
The ratio of boys to girls in a class is 3:7. If there are 35 girls, how many boys are there?
Do it yourself
If 4 pens cost $8, how much will 10 pens cost?
Do it yourself
A recipe requires 2 cups of flour and 4 cups of sugar. If you want to make one-third of the recipe,
how much sugar do you need?
Do it yourself
If a car travels a distance of 90 km in 1.5 hours, what is its speed?
Do it yourself
If it takes 6 hours to paint a room, how much time will it take to paint 6 rooms?
Do it yourself
A map scale is 1 inch equals 40 miles. How far apart are two cities if they are 6 inches apart on
the map?
Do it yourself
If a rectangle has a length of 35 cm and a width of 25 cm, what is its aspect ratio?
Do it yourself
The ratio of students to teachers in a school is 15:2. If there are 75 students, how many teachers
are there?
Do it yourself
Chapter 13 Symmetry
What is symmetry?
Do it yourself
How do you define a line of symmetry?
Do it yourself
Can a shape have multiple lines of symmetry? Explain.
Do it yourself
Are all regular polygons symmetric? Give an example.
Do it yourself
What are asymmetrical shapes? Provide an example.
Do it yourself
Is a circle symmetric? Why or why not?
Do it yourself
How do you identify symmetry in a shape?
Do it yourself
What is rotational symmetry? Give an example.
Do it yourself
Can a shape have both line and rotational symmetry? Explain.
Do it yourself
Name a few natural objects that exhibit symmetry.
Do it yourself
What is bilateral symmetry? Provide an example.
Do it yourself
How do you determine if an image has rotational symmetry?
Do it yourself
Can a letter of the alphabet have symmetry? Give examples.
Do it yourself
Are letters "M" and "W" symmetric? Why or why not?
Do it yourself
How do you identify symmetry in a figure using a mirror?
Do it yourself
Are all quadrilaterals symmetric? Explain.
Do it yourself
Can a figure have infinite lines of symmetry? Give an example.
Do it yourself
List a few everyday objects that have symmetry.
Do it yourself
How do you identify the number of lines of symmetry in a shape?
Do it yourself
Can a figure with curves have symmetry? Explain.
Do it yourself
Is it possible for a shape to have no lines of symmetry? Provide an example.
Do it yourself
What is the difference between symmetrical and congruent shapes?
Do it yourself
Explain the concept of reflection symmetry.
Do it yourself
How can symmetry be used in design and art?
Do it yourself
Are all animals symmetric? Give examples of animals with and without symmetry.
Do it yourself
Can a shape have half symmetry? Explain.
Do it yourself
How does symmetry help us categorize shapes?
Do it yourself
Does every triangle have a line of symmetry? Explain.
Do it yourself
Can you have symmetry in a 3D shape? Provide examples.
Do it yourself
Is an isosceles triangle symmetric? Why or why not?
Do it yourself
What is the significance of symmetry in architecture?
Do it yourself
Can a shape have symmetry if it is not geometric? Give an example.
Do it yourself
Is a rectangle symmetric? Why or why not?
Do it yourself
How is symmetry related to balance?
Do it yourself
Can a shape have more than one line of symmetry but no rotational symmetry? Explain.
Do it yourself
How do you create symmetry in a drawing or painting?
Do it yourself
Are all regular polygons symmetric? Give an example.
Do it yourself
Can an irregular shape have symmetry? Give an example.
Do it yourself
Is a parallelogram symmetric? Why or why not?
Do it yourself
Explain how a kaleidoscope creates symmetrical patterns.
Do it yourself
Can a pentagon have rotational symmetry? Explain.
Do it yourself
How is symmetry used in logo design?
Do it yourself
What is the connection between symmetry and tessellations?
Do it yourself
Can a shape have rotational symmetry but no line of symmetry? Provide an example.
Do it yourself
Explain how symmetry is used in the field of genetics.
Do it yourself
Can you identify symmetry in the human body? Give examples.
Do it yourself
What is the role of symmetry in the study of crystals?
Do it yourself
Can two congruent shapes have different lines of symmetry? Explain.
Do it yourself
How does symmetry help in pattern recognition?
Do it yourself
Can you find symmetry in the letters of your name? Explain.
Do it yourself
Chapter 14 Practical Geometry
What is geometry?
Do it yourself
Define a point in geometry.
Do it yourself
What is a line segment?
Do it yourself
Differentiate between a line and a line segment.
Do it yourself
Name the different types of angles.
Do it yourself
What is a right angle?
Do it yourself
Define a triangle.
Do it yourself
Name the three types of triangles based on their sides.
Do it yourself
What is an equilateral triangle?
Do it yourself
Define a quadrilateral.
Do it yourself
Name four types of quadrilaterals.
Do it yourself
What is a rectangle?
Do it yourself
Explain the concept of congruent figures.
Do it yourself
What is a square?
Do it yourself
Define a parallelogram.
Do it yourself
Differentiate between a rectangle and a square.
Do it yourself
Explain the concept of symmetry.
Do it yourself
What is a line of symmetry?
Do it yourself
Name any two symmetric figures.
Do it yourself
Define a circle.
Do it yourself
Name the parts of a circle.
Do it yourself
What is the circumference of a circle?
Do it yourself
Define a perimeter.
Do it yourself
How is the perimeter of a rectangle calculated?
Do it yourself
Define an area.
Do it yourself
How is the area of a square calculated?
Do it yourself
What is the difference between the perimeter and the area?
Do it yourself
Define the concept of reflection.
Do it yourself
Explain what rotational symmetry is.
Do it yourself
How many lines of symmetry does a triangle have?
Do it yourself
What are concentric circles?
Do it yourself
Define a right-angled triangle.
Do it yourself
How can you identify an isosceles triangle?
Do it yourself
What is the name of a triangle with three unequal sides?
Do it yourself
Define a trapezium.
Do it yourself
What is a rhombus?
Do it yourself
How is the area of a rectangle calculated?
Do it yourself
Define a pentagon.
Do it yourself
What is an obtuse angle?
Do it yourself
How can we determine if two figures are congruent?
Do it yourself
Define an acute angle.
Do it yourself
How many sides does an octagon have?
Do it yourself
What is the difference between a square and a rhombus?
Do it yourself
Define a scalene triangle.
Do it yourself
How many right angles are there in a rectangle?
Do it yourself
Define a hexagon.
Do it yourself
How many lines of symmetry does a regular pentagon have?
Do it yourself
What is the sum of angles in a triangle?
Do it yourself
Define a regular polygon.
Do it yourself
How many sides does a decagon have?
Do it yourself
Science Solutions
Chapter 1 Food Where Does it Come From
1. Question: What is food?
Solution: Food is any substance that provides nutrients when consumed and helps in the growth, repair, and
maintenance of our bodies.
Question: Define agriculture.
Solution: Agriculture is the practice of cultivating plants and rearing animals for food, fiber, medicinal
plants, and other products used to sustain life.
Question: Name the main source of food.
Solution: The main source of food is plants and animals.
Question: What is meant by crop?
Solution: A crop refers to any cultivated plant that is grown and harvested on a large scale for food, feed, or
other economic benefits.
Question: Differentiate between Kharif and Rabi crops.
Solution: Kharif crops are sown in the rainy season and harvested in the winter, while Rabi crops are sown
during winter and harvested in the summer.
Question: What are cereals?
Solution: Cereals are grasses cultivated for their edible grains, such as rice, wheat, maize, barley, etc.
Question: Mention two examples of oilseed crops.
Solution: Mustard and groundnut are examples of oilseed crops.
Question: What do you understand by animal husbandry?
Solution: Animal husbandry refers to the scientific management and breeding of livestock, like cows, goats,
poultry, etc., for agricultural purposes.
Question: Name two methods of crop production.
Solution: The two methods of crop production are traditional and modern farming methods.
Question: Explain organic farming.
Solution: Organic farming is a method of crop production that eliminates the use of synthetic fertilizers,
pesticides, growth regulators, and genetically
modified organisms.
Question: What are the primary sources of obtaining food from animals?
Solution: The primary sources of obtaining food from animals are milk, meat, eggs, and honey.
Question: Define beekeeping.
Solution: Beekeeping is the practice of maintaining bee colonies, usually in hives, to collect honey, beeswax,
and other products.
Question: Describe the role of photosynthesis in food production.
Solution: Photosynthesis is the process through which green plants utilize sunlight, water, and carbon dioxide
to produce carbohydrates (food) and release
oxygen as a byproduct.
Question: What is food chain?
Solution: A food chain is a series of organisms in which each one is eaten by the next member, representing the
flow of energy and nutrients.
Question: What are herbivores?
Solution: Herbivores are animals that solely feed on plants. They do not consume meat.
Question: Define carnivores.
Solution: Carnivores are animals that primarily consume meat or other animal tissue.
Question: Identify an omnivorous animal.
Solution: Humans are considered omnivorous animals as they can consume both plants and animals.
Question: State the importance of food preservation.
Solution: Food preservation is important to prevent spoilage, increase shelf life, maintain nutritional
value,
and avoid food wastage.
Question: Give examples of chemical methods used for food preservation.
Solution: Examples of chemical methods used for food preservation include adding preservatives like salt,
sugar,
vinegar, and artificial preservatives.
Question: Name two diseases caused by malnutrition.
Solution: Two diseases caused by malnutrition are kwashiorkor and marasmus.
Question: Define the term 'food adulteration.'
Solution: Food adulteration refers to the practice of adding substandard or harmful substances to food
products
for economic gain.
Question: How can we prevent food wastage?
Solution: We can prevent food wastage by practicing mindful consumption, proper storage, and donation to
food
banks or charity organizations.
Question: Differentiate between primary and secondary food processing.
Solution: Primary food processing involves converting raw food materials into commodities, while secondary
food
processing involves converting primary
products into ready-to-eat products.
Question: What is cross-pollination?
Solution: Cross-pollination is the transfer of pollen grains from the male reproductive organs of one flower
to
the female reproductive organs of another
flower of the same species.
Question: What is germplasm?
Solution: Germplasm refers to the living genetic resources, such as seeds or other plant propagules, that
can be
used for breeding and maintaining a particular
species.
Question: Explain the term 'organic manure.'
Solution: Organic manure is a natural fertilizer obtained from plant or animal sources, such as compost, cow
dung, poultry litter, green manure, etc.
Question: Name the process in which plant leaves take in carbon dioxide and release oxygen.
Solution: The process is called respiration.
Question: Define the term 'hybridization.'
Solution: Hybridization is the process of breeding two genetically different varieties of plants or animals
to
obtain offspring with desirable characteristics.
Question: Explain the term 'biotechnology.'
Solution: Biotechnology is the use of living organisms, their systems, or their products to produce useful
products or solve various problems.
Question: What is silviculture?
Solution: Silviculture refers to the management and cultivation of forests.
Question: What factors affect crop production?
Solution: Factors like soil fertility, availability of water, sunlight, temperature, rainfall, and the
presence
of pests and diseases affect crop production.
Question: What is meant by precision farming?
Solution: Precision farming is an approach to manage crops and livestock using advanced technology and data
analysis to optimize production efficiency and
minimize resources.
Question: Discuss the advantages of mixed cropping.
Solution: Mixed cropping helps in pest control, better utilization of land, diversification of income, and
reduces the risk of crop failure.
Question: Explain the term 'water harvesting.'
Solution: Water harvesting is the process of collecting and storing rainwater to be used during the dry
seasons
for irrigation purposes.
Question: What are nitrogen-fixing bacteria?
Solution: Nitrogen-fixing bacteria are microorganisms that convert atmospheric nitrogen into a usable form
for
plants, promoting crop growth and reducing
the need for artificial nitrogen fertilizers.
Question: Name an artificial ecosystem.
Solution: A garden or a zoo can be considered an artificial ecosystem.
Question: Define pollination.
Solution: Pollination is the transfer of pollen grains from the male reproductive organs to the female
reproductive organs of a flower, leading to fertilization
and seed formation.
Question: Differentiate between natural and artificial vegetative propagation.
Solution: Natural vegetative propagation occurs through the natural growth and development of vegetative
plant
parts, while artificial vegetative propagation
is achieved by human intervention, such as grafting or layering.
Question: What is aquaculture?
Solution: Aquaculture is the cultivation of aquatic organisms, such as fish, crustaceans, mollusks, and
aquatic
plants, in controlled environments for
commercial purposes.
Question: Explain the concept of food security.
Solution: Food security refers to the availability, accessibility, and affordability of safe and nutritious
food
for all individuals at all times.
Question: What is the importance of crop rotation?
Solution: Crop rotation helps in maintaining soil fertility, reducing pest and disease buildup, and
improving
crop yield by alternating the cultivation of
different crops in a specific sequence.
Question: Discuss the benefits of using biofertilizers.
Solution: Biofertilizers are environmentally friendly, improve soil quality, increase nutrient availability,
and
promote sustainable agriculture.
Question: What are perennial crops?
Solution: Perennial crops refer to plants that have a lifespan of more than two years and continue to
produce
food for multiple cropping seasons.
Question: State the disadvantages of monoculture farming.
Solution: Monoculture farming leads to soil degradation, loss of biodiversity, increased vulnerability to
pests
and diseases, and dependency on chemicals.
Question: Define the term 'harvesting.'
Solution: Harvesting is the process of gathering mature crops from the field when they have reached their
maximum growth stage and are ready for
consumption or further processing.
Question: Explain the concept of Vertical Farming.
Solution: Vertical farming involves cultivating crops in vertically stacked layers or structures, typically
indoors, using hydroponics or aeroponics methods, to
maximize production with limited space and resources.
Question: Name two genetically modified (GM) crops.
Solution: Bt cotton and Bt brinjal (eggplant) are examples of genetically modified crops.
Question: Discuss the impact of deforestation on food production.
Solution: Deforestation leads to soil erosion, loss of habitat for pollinators and other beneficial
organisms,
changes in weather patterns, and overall decline in
food production.
Question: Explain the concept of organic certification.
Solution: Organic certification is a process through which agricultural products are inspected and verified
to
meet the standards set for organic farming
practices, ensuring their authenticity and quality.
Question: What is the role of government in ensuring food security?
Solution: The government plays a crucial role in ensuring food security by formulating and implementing
policies
related to agriculture, trade, distribution,
storage, and providing subsidies to farmers.
Chapter 2 Components of Food
What are nutrients?
Solution: Nutrients are organic and inorganic substances present in food that provide the body with energy
and essential materials for growth, development, and
maintenance.
List the major components of food.
Solution: The major components of food are carbohydrates, proteins, fats, vitamins, minerals, and water.
What is the function of carbohydrates?
Solution: Carbohydrates are the main source of energy for our body. They are responsible for providing
energy for various activities.
Name two types of carbohydrates found in food.
Solution: The two types of carbohydrates found in food are simple carbohydrates (sugars) and complex
carbohydrates (starch and fiber).
Name a rich source of animal protein.
Solution: Meat, fish, eggs, and dairy products are rich sources of animal protein.
What is the function of proteins in our body?
Solution: Proteins are essential for growth, repair, and maintenance of body tissues. They also play a vital
role in the formation of enzymes, hormones, and
antibodies.
Which vitamin is essential for the proper functioning of the immune system?
Solution: Vitamin C is essential for the proper functioning of the immune system.
How can a deficiency of vitamin D be overcome?
Solution: Vitamin D deficiency can be overcome by exposing the body to sunlight and consuming foods rich in
vitamin D, such as fish, fortified milk, and eggs.
What is the primary function of fats in our body?
Solution: Fats provide energy, insulation, and protection to the body organs. They also aid in the
absorption of fat-soluble vitamins.
Name the disease caused by a deficiency of vitamin C.
Solution: The deficiency of vitamin C leads to scurvy.
What is the function of water in our body?
Solution: Water is essential for various body functions, including digestion, nutrient absorption,
circulation, and temperature regulation.
Name the mineral required for the formation of hemoglobin.
Solution: Iron is required for the formation of hemoglobin.
What are the two types of dietary fibers?
Solution: The two types of dietary fibers are soluble fiber and insoluble fiber.
Which food component provides the highest amount of energy per gram?
Solution: Fats provide the highest amount of energy per gram.
What is the difference between saturated and unsaturated fats?
Solution: Saturated fats are solid at room temperature and primarily found in animal sources, while
unsaturated fats are liquid at room temperature and primarily
found in plant sources.
Name a rich source of vitamin A.
Solution: Carrots, spinach, mangoes, and sweet potatoes are rich sources of vitamin A.
What is the recommended daily water intake for an average adult?
Solution: The recommended daily water intake for an average adult is around 8 glasses or 2 liters.
Which component of food is essential for strong bones and teeth?
Solution: Calcium is essential for strong bones and teeth.
Name two water-soluble vitamins.
Solution: Vitamin C and B-complex vitamins are water-soluble vitamins.
What is the function of fiber in our diet?
Solution: Fiber helps in maintaining a healthy digestive system and prevents constipation.
Name a mineral that helps in the regulation of fluid balance in the body.
Solution: Sodium is a mineral that helps in the regulation of fluid balance in the body.
Which nutrient deficiency leads to goiter?
Solution: Iodine deficiency leads to goiter.
Name the disease caused by a deficiency of vitamin B1.
Solution: The deficiency of vitamin B1 leads to beriberi.
What is the main function of carbohydrates in our body?
Solution: Carbohydrates provide energy for the proper functioning of various body systems.
Name a rich source of vitamin C.
Solution: Citrus fruits like oranges and lemons are rich sources of vitamin C.
What is the role of minerals in our body?
Solution: Minerals are essential for the proper functioning of cells, nerve transmission, muscle
contraction, and the formation of body fluids.
Name two trace minerals required by our body in small quantities.
Solution: Iron and zinc are trace minerals required by our body in small quantities.
What is the function of vitamin K in our body?
Solution: Vitamin K plays a crucial role in blood clotting.
Which component of food is responsible for providing instant energy?
Solution: Carbohydrates are responsible for providing instant energy.
Name two functions of water in the body.
Solution: Water helps in regulating body temperature and carrying nutrients and waste products in the
bloodstream.
What is protein-energy malnutrition?
Solution: Protein-energy malnutrition is a condition that occurs due to a lack of both proteins and
calories
in the diet, leading to severe health issues.
Name the two types of vitamins.
Solution: The two types of vitamins are fat-soluble vitamins (A, D, E, and K) and water-soluble vitamins
(B-complex and C).
What is the role of vitamin B12 in our body?
Solution: Vitamin B12 is essential for the synthesis of red blood cells and proper functioning of the
nervous system.
Which mineral is required for muscle contraction and nerve impulse transmission?
Solution: Calcium is required for muscle contraction and nerve impulse transmission.
Name the disease caused by a deficiency of vitamin D.
Solution: The deficiency of vitamin D leads to rickets in children and osteomalacia in adults.
What is the function of vitamin E in our body?
Solution: Vitamin E acts as an antioxidant, protecting cell membranes from damage.
Which food component provides a feeling of fullness and prevents overeating?
Solution: Dietary fiber provides a feeling of fullness and prevents overeating.
Name a rich source of vitamin K.
Solution: Green leafy vegetables like spinach and kale are rich sources of vitamin K.
What is the recommended daily intake of protein for an average adult?
Solution: The recommended daily intake of protein for an average adult is around 50 grams.
Which nutrient is required for the production of energy from food?
Solution: B-complex vitamins are required for the production of energy from food.
Name a mineral required for the formation of strong teeth.
Solution: Fluoride is required for the formation of strong teeth.
What is the function of vitamin A in our body?
Solution: Vitamin A is essential for healthy vision, growth, and development, particularly of bones
and
teeth.
Name the disease caused by a deficiency of iron.
Solution: The deficiency of iron leads to anemia.
What is the function of vitamin B2 in our body?
Solution: Vitamin B2 is essential for the conversion of carbohydrates into energy.
Which food component is necessary for the transport of fat-soluble vitamins in the body?
Solution: Fats are necessary for the transport of fat-soluble vitamins in the body.
Name a rich source of vitamin B1.
Solution: Whole grains like wheat and rice are rich sources of vitamin B1.
What is the function of vitamin B6 in our body?
Solution: Vitamin B6 is involved in the metabolism of proteins and fats.
Which component of food provides building blocks for the growth and repair of tissues?
Solution: Proteins provide building blocks for the growth and repair of tissues.
Name a rich source of vitamin B12.
Solution: Animal products like meat, fish, eggs, and dairy products are rich sources of vitamin B12.
What is the recommended daily intake of fruits and vegetables for an average adult?
Solution: The recommended daily intake of fruits and vegetables for an average adult is around 5
servings.
Chapter 3 Fibre to Fabric
Q: What are natural fibers? Give examples.
A: Natural fibers are obtained from plants and animals. Examples include cotton, silk, wool, and
jute.
Q: Name two synthetic fibers.
A: Nylon and polyester are examples of synthetic fibers.
Q: Define the process of spinning.
A: Spinning is the process of making fibers into yarns or threads.
Q: What is ginning? Mention its purpose.
A: Ginning is the process of separating cotton fibers from their seeds. It ensures the removal
of
impurities and prepares the fiber for spinning.
Q: Explain the term "sericulture."
A: Sericulture is the rearing of silkworms for the production of silk.
Q: What are the sources of obtaining wool?
A: Sheep, goat, yak, camel, and rabbit are the common sources of obtaining wool.
Q: Name the fibers that are obtained from plants.
A: Fibers obtained from plants include cotton, jute, and coir.
Q: Why is the process of making fabric from fibers called weaving?
A: The process of arranging two sets of yarns together to make fabric is called weaving.
Q: Define retting. Where is it commonly used?
A: Retting is the process of separating fibers from jute plants. It is commonly used in India
and
Bangladesh.
Q: How is fabric formed from fibers in the process of knitting?
A: In knitting, a single yarn is used to make fabric by interlocking loops.
Q: Which insect is responsible for silk production?
A: Silkworms are responsible for silk production.
Q: Name two animal fibers that are obtained without killing the animal.
A: Angora wool (from rabbits) and Pashmina wool (from goats) are obtained without killing the
animals.
Q: What is the most common method for preparing fibers for spinning?
A: Carding is the most common method for preparing fibers for spinning.
Q: Explain the term "yarn."
A: Yarn is a continuous strand made by fibers twisted together.
Q: How can you differentiate between natural and synthetic fibers?
A: Natural fibers are obtained from plants and animals, while synthetic fibers are human-made.
Q: Which fiber is known as the "King of Fibers" and why?
A: Silk is known as the "King of Fibers" because of its luxurious and delicate nature.
Q: What is the process of dyeing?
A: Dyeing is the process of adding colors to fibers or fabrics.
Q: State the differences between woven and knitted fabrics.
A: Woven fabrics are made by interlacing two sets of yarns, while knitted fabrics are made by
interlocking loops.
Q: How is wool obtained from sheep?
A: Wool is obtained from sheep by shearing their fleece.
Q: Give examples of synthetic fibers used in making clothes.
A: Examples of synthetic fibers used in making clothes are polyester, nylon, and acrylic.
Q: Define scouring. Why is it important in the wool industry?
A: Scouring is the process of removing grease, oil, and dirt from wool. It is important to make
the
wool clean before further processing.
Q: What is decortication used for?
A: Decortication is used to separate fibers from the stem of jute plants.
Q: Name some common plant fibers used in the textile industry.
A: Cotton, jute, flax, and hemp are some common plant fibers used in the textile industry.
Q: What are the characteristics of synthetic fibers that make them popular?
A: Synthetic fibers are durable, wrinkle-resistant, easy to maintain, and come in a wide range
of
colors.
Q: How does retting help in the separation of bast fibers from the plant stem?
A: Retting helps to remove unwanted fibers and makes the separation of bast fibers from the
plant
stem easier.
Q: What is the difference between filament and staple fibers?
A: Filament fibers are continuous, while staple fibers are short in length.
Q: Explain the life cycle of a silkworm.
A: The life cycle of a silkworm includes the egg stage, larva stage (silkworm), pupa stage,
and
adult moth stage.
Q: What is the role of the "Rearing House" in the silk production process?
A: The rearing house provides a suitable environment for silkworms to feed, grow, and spin
cocoons.
Q: How can you distinguish between animal and plant fibers?
A: Animal fibers are made of proteins, while plant fibers are composed of cellulose.
Q: What is the process of separating cotton fibers from seeds known as?
A: The process of separating cotton fibers from seeds is known as ginning.
Q: Differentiate between natural and regenerated fibers.
A: Natural fibers are obtained directly from plants and animals, while regenerated fibers
are made
from natural materials through chemical processes.
Q: Name some diseases common among silkworms.
A: The common diseases among silkworms include grasserie, muscardine, and flacherie.
Q: What are the disadvantages of synthetic fibers?
A: Synthetic fibers are non-biodegradable, do not allow the skin to breathe, and can melt
when
exposed to heat.
Q: How is the process of blending fibers beneficial in the textile industry?
A: Blending fibers helps enhance the characteristics of different fibers, making the fabric
more
durable, comfortable, and cost-effective.
Q: How does bleaching help in the textile industry?
A: Bleaching helps in the removal of natural color or stains from fibers or fabrics,
providing a
pure white base for further dyeing or printing.
Q: What is the source of obtaining jute fiber?
A: The jute fiber is obtained from the stem of the jute plant.
Q: Mention any two properties of cotton that make it suitable for making summer
clothes.
A: Cotton is breathable and has good moisture-absorbing properties, making it suitable for
making
summer clothes.
Q: Explain the process of dyeing with specific examples.
A: Dyeing is the process of adding colors to fibers or fabrics. For example, adding indigo
dye to
cotton yarn or dyeing silk with natural dyes like turmeric.
Q: Why is it important to brush wool fibers during processing?
A: Brushing wool fibers helps align the fibers, remove impurities, and give the wool a
smooth and
lustrous appearance.
Q: How does the "Rota" machine help in the production of cotton fibers?
A: The Rota machine combs the fibers, straightens them, and removes any remaining impurities
after
the ginning process.
Q: Define the term "felting."
A: Felting is the process of matting wool fibers together to form a dense fabric, often
without the
use of weaving or knitting.
Q: What is the process of "carbonization" used for?
A: Carbonization is used to remove plant materials, such as seed coats or leaf fragments,
from the
cellulose fibers of cotton or jute.
Q: How are different properties of fabrics determined in a laboratory?
A: Different properties of fabrics, such as strength, durability, and colorfastness, can be
determined through various laboratory tests.
Q: What is the role of the "loom" in the textile industry?
A: The loom is a device used to weave yarns into fabric by interlacing them at right angles.
Q: Why is silk considered a luxury fabric?
A: Silk is considered a luxury fabric due to its natural shine, smoothness, and expensive
production
process.
Q: Explain the term "regeneration" in the context of synthetic fibers.
A: Regeneration is the process of converting natural materials into fibers through chemical
treatments, as in the production of viscose rayon.
Q: How are synthetic fibers different from natural fibers in terms of water absorption?
A: Synthetic fibers have low water absorption, while natural fibers like cotton have high
water
absorption.
Q: Name the government body responsible for silk production in India.
A: The Central Silk Board (CSB) is the government body responsible for silk production in
India.
Q: State the process of making fabric from yarns through hand knitting.
A: Hand knitting involves using knitting needles to interlock loops of yarns and create
fabric.
Q: Explain the process of "winding."
A: Winding is the process of transferring yarns from one package or form to another, usually
onto a
cone or spool, for further processing or use.
Chapter 4 Sorting Materials into Groups
Question 1:
Define the term 'sorting' and explain its importance in our daily life.
Solution:
Sorting refers to the process of arranging or classifying objects based on their
similarities and differences. It helps in organizing materials, identifying
similarities, and establishing a systematic order, making tasks more manageable.
Question 2:
Differentiate between heterogeneous and homogeneous materials, providing examples for
each.
Solution:
Heterogeneous materials consist of components that can be easily distinguished, while
homogeneous materials have uniform composition. For example, a
mixture of sand and iron filings is heterogeneous, whereas salt dissolved in water is a
homogeneous mixture.
Question 3:
What are the physical properties that can be used for sorting materials? Explain three
of
these properties.
Solution:
Physical properties such as color, shape, size, texture, and density can be used for sorting
materials. For example, while sorting fruits, we can use color, shape,
and size to classify them.
Question 4:
Explain the process of sieving along with its application in daily life.
Solution:
Sieving is a method used to separate solids of different sizes using a sieve or a mesh. It
is commonly used in the kitchen to separate fine flour from lumps or
impurities. It is also used in construction to separate stones of different sizes for
various purposes.
Question 5:
Classify the following materials as solid, liquid, or gas: Oxygen, coal, water, and
mercury.
Solution:
Oxygen and coal are gases, water is a liquid, and mercury is a liquid metal at room
temperature.
Question 6:
Differentiate between metals and non-metals based on their properties.
Solution:
Metals are usually hard, malleable, ductile, conductors of heat and electricity, while
non-metals are brittle, poor conductors of heat and electricity, and lack
metallic luster.
Question 7:
What are the various methods of separating mixtures? Explain any two of them.
Solution:
Methods of separation include evaporation, filtration, distillation, sublimation, magnetic
separation, etc. For example, filtration is used to separate insoluble
solids from liquids, while distillation is used to separate liquids based on their boiling
points.
Question 8:
Give an example of a natural polymer and a synthetic polymer.
Solution:
Natural polymer: Proteins, such as silk or wool.
Synthetic polymer: Polyethylene, used to make plastic bags.
Question 9:
State the differences between solutions, suspensions, and colloids with suitable
examples.
Solution:
Solutions are homogeneous mixtures where solute particles dissolve uniformly in the solvent
(e.g., salt dissolved in water). Suspensions are heterogeneous
mixtures where solid particles do not dissolve but are suspended (e.g., muddy water).
Colloids are mixtures where particles are dispersed throughout another
substance in a dispersed phase (e.g., milk).
Question 10:
Explain why alloys are considered to be homogeneous mixtures.
Solution:
Alloys are considered homogeneous mixtures because the metals in them are evenly distributed
at the atomic level. For example, brass, which is an alloy of
copper and zinc, has a uniform composition.
Question 11:
Describe the method used for separating cream from milk.
Solution:
Cream can be separated from milk by the process of centrifugation. When milk is rotated at
high speed in a centrifuge, the heavier milk solids settle at the
bottom, while the lighter cream accumulates at the top.
Question 12:
Name five elements that can act as catalysts and explain their importance.
Solution:
Some common elements acting as catalysts are iron, nickel, platinum, manganese, and copper.
Catalysts speed up chemical reactions without being consumed
themselves, making them crucial in industries for increasing reaction rates and reducing
costs.
Question 13:
Differentiate between a compound and a mixture, providing examples for each.
Solution:
A compound consists of two or more elements chemically bonded together. Example: Water
(H?O). A mixture is a combination of two or more substances that
are physically mixed but can be separated. Example: Air (a mixture of nitrogen, oxygen,
carbon dioxide, etc.).
Question 14:
Explain the process of decantation and its applications.
Solution:
Decantation is a separation technique used to separate two immiscible liquids or a liquid
and solid. The mixture is left undisturbed, allowing the denser
component to settle at the bottom. The clear liquid is then poured off carefully. It is
commonly used to separate oil from water or to separate sediment from a
liquid.
Question 15:
Define the term 'chromatography' and explain its use in separating colors.
Solution:
Chromatography is a technique used to separate a mixture of different colored substances by
allowing them to move at different rates along a medium. It finds
applications in separating colors in ink, pigments, or dyes.
Question 16:
Name the process used to separate a colored component from a mixture.
Solution:
The process used to separate a colored component from a mixture is called extraction. It
involves selectively dissolving the desired component in a suitable
solvent, leaving behind the other components.
Question 17:
Explain the process of sterilization and its importance in our daily lives.
Solution:
Sterilization is a process used to eliminate or destroy microorganisms (bacteria, viruses,
etc.) from objects or surfaces. It is crucial in hospitals, laboratories, and
industries to prevent the spread of diseases and maintain hygiene.
Question 18:
State the difference between a physical change and a chemical change, giving examples
for
each.
Solution:
Physical change refers to a change in the physical properties of a substance without
altering its chemical composition. Example: Melting ice into water.
Chemical change refers to a change that results in the formation of a new substance with new
chemical properties. Example: Burning paper.
Question 19:
Define the term 'adsorption'. Explain its significance in industrial processes.
Solution:
Adsorption is a process where molecules of a substance adhere to the surface of another
substance. It is significant in industrial processes like purification of
drinking water, removal of impurities from air, or catalytic reactions.
Question 20:
Explain how alloys are more useful than pure metals in various applications.
Solution:
Alloys are more useful than pure metals since they often possess improved properties like
increased strength, resistance to corrosion, heat resistance, etc. For
example, steel is an alloy of iron and carbon, which exhibits higher strength and corrosion
resistance compared to pure iron.
Question 21:
Describe the process of isolating and separating ethene gas from a mixture.
Solution:
Ethene gas can be isolated and separated from a mixture of gases by using the technique of
fractional distillation. The mixture is heated, and different gases are
separated based on their boiling points.
Question 22:
What do you understand by the term 'plastic recycling'? Elaborate on its benefits.
Solution:
Plastic recycling refers to the process of collecting used plastic products, breaking them
down, and converting them into new plastic products. It helps reduce
environmental pollution, conserve resources, and minimize the demand for new plastic
production.
Question 23:
How can you separate a mixture of sawdust and sand? Explain the process.
Solution:
A mixture of sawdust and sand can be separated by the process of winnowing. The mixture is
allowed to flow in the presence of a breeze, and as the sand is
denser, it falls down while the lighter sawdust is blown away.
Question 24:
Explain the significance of chromatography in forensic science.
Solution:
Chromatography plays a crucial role in forensic science for analyzing crime scene evidence
like ink, drugs, or stains. By separating the different components, it
helps identify substances used and aids in investigations.
Question 25:
Differentiate between metals and non-metals based on their chemical properties.
Solution:
Metals generally have the tendency to lose electrons and form positive ions. Non-metals tend
to gain electrons and form negative ions. This fundamental
difference in their behavior distinguishes their chemical properties.
Question 26:
Describe the method used for separating iodine crystals from a mixture.
Solution:
Iodine crystals can be separated from a mixture by using the process of sublimation. Under
suitable conditions, iodine directly changes from a solid to a gaseous
state without melting, and the vapor can be collected separately and then cooled to form
crystals again.
Question 27:
What do you understand by bio-degradable and non-biodegradable substances? Provide
examples
for both.
Solution:
Biodegradable substances are those that can be broken down naturally by living organisms
into simpler substances. Example: Food waste. Non-biodegradable
substances are those that cannot be easily broken down by natural processes. Example:
Plastic.
Question 28:
Explain the role of sieving in construction and agriculture industries.
Solution:
In the construction industry, sieving helps separate different sizes of aggregates for
concrete or grading of sand. In agriculture, sieving helps separate stones,
impurities, or unwanted materials from crops or grains.
Question 29:
Differentiate between crystalline and amorphous solids with suitable examples.
Solution:
Crystalline solids have a definite and ordered arrangement of particles, forming
well-defined geometric shapes. Example: Sodium chloride (table salt).
Amorphous solids lack a definite pattern and have a random arrangement of particles.
Example: Glass.
Question 30:
Explain how fractional distillation is used in the petroleum industry.
Solution:
Fractional distillation is used in the petroleum industry to separate crude oil into
different components according to their boiling points. This process allows the
extraction of useful products like gasoline, diesel, kerosene, etc.
Question 31:
Define the term 'emulsion'. Provide an example.
Solution:
An emulsion is a colloid where two immiscible liquids are dispersed in each other, forming a
stable mixture. Example: Milk is an emulsion of fat globules
dispersed in water.
Question 32:
What are the advantages and disadvantages of using plastic materials?
Solution:
Advantages of using plastic materials include durability, versatility, lightweight, and ease
of manufacturing. Disadvantages include environmental pollution,
non-biodegradability, and potential health hazards.
Question 33:
Explain the process of filtration along with its applications.
Solution:
Filtration is a method used to separate insoluble solids from liquids or gases using a
filter medium. It finds applications in the purification of water, air,
laboratory processes, and industrial filtration systems.
Question 34:
Differentiate between a chemical mixture and a physical mixture.
Solution:
A chemical mixture involves a chemical reaction, resulting in the formation of new
substances with different properties. A physical mixture involves a
reversible change in physical properties, without altering the chemical composition.
Question 35:
What do you understand by the term 'electrolysis'? Explain its applications.
Solution:
Electrolysis refers to the process of using an electric current to decompose compounds into
their constituent elements. It finds applications in electroplating,
metal purification, electrorefining, and the production of various chemicals.
Question 36:
Differentiate between optical isomers and chemical isomers.
Solution:
Optical isomers are stereoisomers that have the same chemical formula and connectivity but
differ in their spatial arrangement. Chemical isomers are
compounds that have the same molecular formula but differ in their connectivity.
Question 37:
Explain why carbon compounds exhibit a wide range of properties.
Solution:
Carbon compounds exhibit a wide range of properties due to the presence of carbon atoms that
can form multiple bonds with other atoms, resulting in versatile
chemical structures. This versatility allows the formation of various organic compounds with
distinct properties.
Question 38:
Elaborate on the role of winnowing in agriculture.
Solution:
Winnowing plays a vital role in agriculture for separating grains from unwanted parts like
chaff, husks, or straw. It involves tossing the mixture in the air,
allowing the wind to blow away the lighter impurities while the heavier grains fall down.
Question 39:
Discuss the various methods used for separating a mixture of salt dissolved in water.
Solution:
To separate salt from water, methods such as evaporation, crystallization, or distillation
can be used. In evaporation, the water is heated and evaporated, leaving
behind salt crystals. Crystallization involves cooling the solution until the salt
crystallizes. Distillation involves heating the solution and collecting the condensed
water separately.
Question 40:
Why is it important to separate waste materials into different categories during waste
disposal? Explain.
Solution:
Separating waste materials into different categories during waste disposal is important
because it enables proper recycling, treatment, or disposal mechanisms
for different types of waste. It promotes sustainability, minimizes environmental pollution,
and conserves resources.
Question 41:
Describe the process of filtration used in kidney dialysis.
Solution:
Filtration in kidney dialysis is a medical process that involves removing waste products and
excess water from the blood by passing it through a special filter
called a dialyzer. The filter selectively allows small molecules and waste to pass through
while retaining necessary substances.
Question 42:
What is the role of indicator solutions in chemistry? Provide examples.
Solution:
Indicator solutions are substances used to determine the presence or absence of certain
chemicals in a solution by changing color. For example, phenolphthalein
is used as an indicator to determine the acidity or basicity of a solution.
Question 43:
Differentiate between mixtures and compounds, providing three key differences.
Solution:
Mixtures are combinations of two or more substances that can be physically separated.
Compounds are substances composed of two or more elements
chemically bonded together.
Key differences:
1. Mixtures can be separated physically, while compounds can only be separated chemically.
2. Mixtures have variable composition, while compounds have fixed composition.
3. Mixtures retain the properties of the individual components, whereas compounds often have
different properties.
Question 44:
Explain how recycling contributes to environmental conservation.
Solution:
Recycling reduces the consumption of raw materials, conserves energy, reduces pollution
associated with manufacturing, and reduces waste sent to landfills. By
recycling, we can lessen the burden on natural resources, reduce greenhouse gas emissions,
and protect the environment.
Question 45:
Describe the process of magnetic separation and its applications.
Solution:
Magnetic separation involves using a magnet to attract and separate magnetic substances from
a mixture. It is used in recycling plants to separate magnetic
materials from non-magnetic ones, in the mining industry for mineral separation, and for
removing impurities from food products.
Question 46:
What role does sorting play in the field of material recycling?
Solution:
Sorting plays a crucial role in material recycling by enabling the separation of different
types of waste materials. It allows efficient recycling processes and
ensures that materials are directed to appropriate recycling facilities, reducing
environmental impact and maximizing resource utilization.
Question 47:
Explain the process of settling with the help of examples.
Solution:
Settling is a method used to separate solid particles from a liquid by allowing them to
settle down due to gravity. Examples include suspensions like muddy
water, where the sediment settles at the bottom with time.
Question 48:
Differentiate between elements and compounds, providing examples for each.
Solution:
Elements are substances made up of a single type of atom, and compounds are substances made
up of two or more types of atoms chemically bonded together.
Examples of elements: Oxygen (O), Helium (He).
Examples of compounds: Water (H?O), Carbon dioxide (CO?).
Question 49:
Define the term 'emulsifier' and provide examples.
Solution:
An emulsifier is a substance that helps stabilize an emulsion by reducing the surface
tension between immiscible liquids. Examples of emulsifiers include
lecithin used in food emulsions and soap used in cleaning emulsions.
Question 50:
Why is it important to sort waste into organic and inorganic components during waste
management? Explain.
Solution:
Sorting waste into organic and inorganic components during waste management is important
because it allows different treatment methods. Organic waste can
be converted into compost or used for biogas production, while inorganic waste can be
recycled or disposed of separately. This ensures maximum utilization of
resources, reduces environmental pollution, and promotes sustainable waste management
practices.
Chapter 5 Separation of Substances
Q1: Define the term 'separation of substances'.
A1: Separation of substances refers to the process of dividing a mixture into its individual
components or constituents.
Q2: What are the different methods of separation of substances?
A2: The different methods of separation of substances include filtration, evaporation,
decantation, centrifugation, magnetic separation, and chromatography.
Q3: Explain the process of filtration.
A3: Filtration is a method of separating solid particles from a liquid or gas mixture using
a filter medium. The mixture is poured through the filter, and the solid
particles get trapped while the liquid or gas passes through.
Q4: What is evaporation? How is it useful for separation?
A4: Evaporation is the process of converting a liquid into its gaseous state by heating. It
is useful for separating a soluble solid from a liquid by heating the
mixture until the liquid evaporates, leaving behind the solid.
Q5: Describe the process of decantation.
A5: Decantation is a method of separation used to separate a mixture of a solid and liquid.
In this process, the mixture is left undisturbed until the solid settles at
the bottom. The liquid is then carefully poured out, leaving the solid behind.
Q6: What is centrifugation? How does it work?
A6: Centrifugation is a technique that uses centrifugal force to separate substances of
different densities. The mixture is spun rapidly in a centrifuge, causing the
denser components to settle at the bottom while the less dense components remain on top.
Q7: Explain magnetic separation with an example.
A7: Magnetic separation is a process that uses magnets to separate magnetic substances from
non-magnetic ones. For example, a mixture of iron filings and
sulfur powder can be separated using a magnet. The iron filings will be attracted to the
magnet, leaving the sulfur behind.
Q8: What is chromatography? How is it used for separation?
A8: Chromatography is a technique used to separate components of a mixture based on their
ability to move through a medium. It involves the use of a
stationary phase and a mobile phase. The mixture is applied to the stationary phase, and as
the mobile phase moves through, different components move at
different rates, allowing for separation.
Q9: Differentiate between decantation and filtration.
A9: Decantation is used to separate a mixture of solid and liquid by allowing the solid to
settle and pouring out the liquid, while filtration is used to separate
solid particles from a liquid or gas mixture using a filter.
Q10: Explain how sieving is a method of separation.
A10: Sieving is a method of separation that uses a sieve or a mesh to separate larger
particles from smaller particles. It is commonly used to separate different
sizes of grains or powders.
Q11: What is sublimation? Give an example.
A11: Sublimation is a process in which a solid directly changes into a gaseous state without
becoming a liquid. An example of sublimation is the conversion of
solid iodine into iodine vapor upon heating.
Q12: How does the process of distillation work?
A12: Distillation is a method of separation that utilizes the differences in boiling points
of substances. The mixture is heated, and the component(s) with lower
boiling points vaporize, which are then condensed and collected.
Q13: Explain the principle of handpicking as a method of separation.
A13: Handpicking is a simple method of separation where individual components of a mixture
are picked up by hand. It is typically used to separate larger solid
items, such as picking out stones from grains.
Q14: What is winnowing? How is it used for separation?
A14: Winnowing is a method of separation used to separate heavier particles from lighter
particles using wind. The mixture is tossed in the air, and heavier
particles fall back, while lighter particles are carried away by the wind.
Q15: Describe the process of crystallization in the separation of substances.
A15: Crystallization is a method used to obtain purified solid substances from a solution.
The solution is heated until it becomes saturated, and then it is allowed
to cool slowly. This leads to the formation of pure crystals, while impurities remain in the
solution.
Q16: How is evaporation different from boiling? Provide an example.
A16: Evaporation occurs at any temperature, but boiling specifically involves the conversion
of a liquid into vapor at its boiling point. For example, when water
is heated, it slowly evaporates at room temperature, but when it reaches its boiling point
(100°C), it boils rapidly and vaporizes.
Q17: What is the purpose of using a separating funnel?
A17: A separating funnel is used to separate immiscible liquids, such as oil and water. It
works based on the difference in densities of the two liquids. The
denser liquid settles at the bottom, allowing for separation by opening the stopcock.
Q18: Explain fractional distillation and its application.
A18: Fractional distillation is a method used for the separation of a mixture of two or more
miscible liquids. It is based on the differences in boiling points of the
liquids. This technique is extensively used in the petroleum industry to separate crude oil
into its various components like gasoline, diesel, kerosene, etc.
Q19: How does paper chromatography work?
A19: Paper chromatography is a technique used to separate mixtures into their individual
components based on their different solubilities. A paper strip acts as
the stationary phase, and a liquid solvent acts as the mobile phase. As the solvent moves up
the paper strip, the components of the mixture separate and form
distinct bands.
Q20: Discuss the application of sieving in our daily lives.
A20: Sieving finds its application in various aspects of our daily lives. For instance, it
is used in the kitchen to separate flour from any impurities, in construction
to separate gravel from sand, or in laboratories to separate particles of different sizes.
Q21: Differentiate between suspension and colloid.
A21: A suspension is a heterogeneous mixture in which solid particles or liquid droplets are
dispersed in a liquid or gas, while a colloid is a homogeneous
mixture in which particles of one substance are dispersed evenly throughout another
substance, usually forming a thicker consistency.
Q22: Explain the method of handwashing as a practical example of separation.
A22: Handwashing is a practical example of separation that involves separating dirt, germs,
and bacteria from our hands using soap and water. The soap
molecules bind with the dirt and microbes, making it easier to rinse them away with water.
Q23: How does the process of sedimentation contribute to separation?
A23: Sedimentation is the process where solid particles settle at the bottom of a liquid due
to gravitational force. It aids in the separation of solid materials from
liquids, as the settled particles can be easily separated by decantation.
Q24: What is the purpose of using a centrifuge in separation techniques?
A24: A centrifuge is used to separate substances of different densities by spinning them
rapidly. It increases the gravitational force acting on the mixture,
allowing the denser components to settle at the bottom while the less dense components
remain on top.
Q25: Discuss the role of filtration in the purification of drinking water.
A25: Filtration plays a crucial role in the purification of drinking water. It helps to
remove suspended impurities and solid particles, making water safe for
consumption. Various filtration techniques are used, such as using sand beds, activated
charcoal filters, or ceramic filters.
Q26: How can we separate a mixture of salt and water?
A26: The mixture of salt and water can be separated by the process of evaporation. When the
mixture is heated, the water evaporates and leaves behind the salt.
The salt can then be collected and obtained in its pure form.
Q27: Discuss the importance of separation techniques in industries.
A27: Separation techniques are of great importance in industries for various purposes. They
are used to obtain pure substances from impure mixtures, segregate
different components for further processing, or remove harmful pollutants from waste
materials, ensuring environmental sustainability.
Q28: What are some common everyday examples of chromatography?
A28: Some common examples of chromatography in our daily lives include using marker pens
on
paper, where the ink spreads out into different colors as the
solvent moves, or when the colors in candy coatings separate when they come into contact
with moisture.
Q29: How does magnetic separation contribute to recycling processes?
A29: Magnetic separation plays a significant role in recycling processes, particularly
for
separating ferromagnetic materials such as iron and steel from waste
streams. Magnets are used to attract and separate these metals, allowing for their
recovery
and reuse.
Q30: Discuss how fractional distillation is used in the production of alcoholic
beverages.
A30: Fractional distillation is used in the production of alcoholic beverages to
separate
alcohol from other components in fermented mixtures. By heating the
fermented mixture, the alcohol vaporizes, while unwanted components like water and
impurities are left behind.
Q31: Explain the process of reverse osmosis and its role in water purification.
A31: Reverse osmosis is a separation process that uses a semi-permeable membrane to
remove
impurities from water. The impure water is subjected to high
pressure, forcing it through the membrane. This process effectively removes
contaminants,
ensuring clean and purified water.
Q32: How is the process of sieving different from that of decantation?
A32: Sieving involves the separation of larger particles from smaller particles using a
sieve or mesh, while decantation is the separation of a solid-liquid mixture
by allowing the solid to settle and carefully pouring out the liquid.
Q33: Describe the technique of handpicking and its limitations.
A33: Handpicking involves manually separating individual components of a mixture using
our
hands or tools. However, it is only suitable for larger and easily
distinguishable items, and it is not efficient for separating smaller or similar-sized
particles.
Q34: What is the role of separation techniques in forensic science?
A34: Separation techniques are vital in forensic science for analyzing crime scene
evidence.
For example, chromatography can be used to separate ink from
fraudulent documents, or spectroscopy can be used to analyze different components of a
drug
mixture.
Q35: How does magnetic separation contribute to mining operations?
A35: Magnetic separation is extensively used in mining operations to remove magnetic
impurities from minerals. It helps in obtaining purer and higher-grade
minerals by separating them from impurities such as iron ore.
Q36: Discuss the significance of chromatography in the pharmaceutical industry.
A36: Chromatography is widely used in the pharmaceutical industry for drug analysis,
quality
control, and purification. It helps in separating and identifying
various active ingredients, ensuring their purity and effectiveness in medicines.
Q37: Explain how a centrifuge is used to separate blood components in medical
laboratories.
A37: In medical laboratories, a centrifuge is used to separate blood components such as
red
blood cells, white blood cells, and plasma. The high-speed rotation
of the centrifuge separates these different components based on their densities.
Q38: What is the role of decantation in the production of vegetable oils?
A38: Decantation is used in the production of vegetable oils to separate them from other
impurities, such as water or solid particles, that may be present after
extraction. The oil is left to settle, and then the clear upper layer is carefully
poured
out, separating it from unwanted substances.
Q39: How does the separation of substances impact recycling efforts?
A39: The separation of substances plays a crucial role in recycling efforts by allowing
different materials to be sorted and processed individually. It enhances the
efficiency of recycling processes and enables the recovery of valuable resources from
waste.
Q40: Discuss the role of separation techniques in food processing industries.
A40: Separation techniques are extensively used in food processing industries for
various
purposes, such as separating solid impurities from liquids, removing
unwanted components, extracting flavorings, or concentrating desired components like
fruit
juices.
Q41: Explain the role of filtration in air purification systems.
A41: Filtration is a critical component in air purification systems as it helps in
removing
dust particles, pollutants, and allergens from the air, providing cleaner
and healthier indoor environments.
Q42: What is the importance of separation techniques in wastewater treatment plants?
A42: Separation techniques are essential in wastewater treatment plants for separating
pollutants and contaminants from wastewater before it is discharged back
into the environment. These techniques aid in the removal of solid particles, organic
matter, and harmful chemicals, ensuring cleaner water bodies.
Q43: Discuss the process of electrostatic separation and its applications.
A43: Electrostatic separation uses the differences in electrical charges of particles to
separate them. It is utilized in applications like recycling plastic waste,
where different plastic polymers are separated based on their electrostatic properties.
Q44: How can separation techniques be applied in the field of environmental science?
A44: Separation techniques are applied in environmental science to analyze the
composition
and pollutants in air, water, and soil samples. They help in
identifying and quantifying various pollutants, which aids in developing measures for
environmental protection.
Q45: Explain how fractional distillation is used in the petroleum industry.
A45: Fractional distillation is an essential process in the petroleum industry for
separating crude oil into various components based on their boiling points. It
allows the production of different fractions like gasoline, diesel, or kerosene, which
have
specific applications.
Q46: Discuss the role of separation techniques in the production of biofuels.
A46: Separation techniques are crucial in the production of biofuels from various
biomass
sources. They help in separating and purifying the desired fuel
components, such as ethanol or biodiesel, from the complex mixture of biomass.
Q47: What is the significance of separation techniques in the recycling of electronic
waste?
A47: Separation techniques play a vital role in recycling electronic waste, also known
as
e-waste. They help in separating valuable components like metals from
the waste stream, reducing the environmental impact and maximizing resource recovery.
Q48: Explain the method of chromatography used for the analysis of pigments in
plants.
A48: Chromatography is commonly used for the analysis of pigments in plants, such as
chlorophyll. By allowing a solvent to move up a paper strip containing
the pigment extract, the different pigments separate and create distinct bands, allowing
for
identification.
Q49: What is the role of separation techniques in the pharmaceutical industry's drug
development process?
A49: Separation techniques are integral to the drug development process in the
pharmaceutical industry. They help in separating, isolating, and purifying active
pharmaceutical ingredients (APIs) from complex mixtures, ensuring the safety and
effectiveness of medicines.
Q50: Discuss the role of separation techniques in DNA extraction and analysis.
A50: Separation techniques are crucial in DNA extraction and analysis for separating DNA
from other cellular components. Methods like centrifugation,
chromatography, and electrophoresis are used to extract, separate, and analyze DNA
samples,
allowing for genetic research, diagnostics, and forensic
investigations.
Chapter 6 Changes Around Us
1. Q: What is a physical change?
A: A physical change is a change that affects the physical properties of a substance
without altering its chemical composition.
2. Q: Give an example of a physical change.
A: Breaking a glass bottle into pieces is an example of a physical change.
3. Q: Define chemical change.
A: A chemical change refers to a process that results in the formation of new substances
with different properties.
4. Q: Name a chemical change that you observe in your daily life.
A: The rusting of iron is an example of a chemical change.
5. Q: What do you mean by reversible change?
A: A reversible change is a change that can be reversed, and the original substance can
be obtained again.
6. Q: Give an example of a reversible change.
A: Melting of ice is a reversible change.
7. Q: Define irreversible change.
A: An irreversible change is a change that cannot be undone, and the original
substance
cannot be obtained again.
8. Q: Name an irreversible change that you experience at home.
A: Burning of a paper is an irreversible change.
9. Q: What is evaporation?
A: Evaporation is the process of conversion of a liquid into its vapor or gas phase
at a
temperature below its boiling point.
10. Q: Explain condensation.
A: Condensation is the process by which a vapor or gas turns into a liquid.
11. Q: Define sublimation.
A: Sublimation is the process in which a solid directly converts into a gas without
passing through the liquid phase.
12. Q: Give an example of sublimation.
A: The conversion of solid camphor into its vapor form is an example of sublimation.
13. Q: What is melting?
A: Melting is the process of conversion of a solid into a liquid due to the increase
in
temperature.
14. Q: Explain freezing.
A: Freezing is the process in which a liquid converts into a solid due to the
decrease
in temperature.
15. Q: State the effect of heat on matter.
A: Heat generally causes expansion in matter.
16. Q: Describe the effect of cold on matter.
A: Cold generally causes contraction in matter.
17. Q: What are the different states of matter?
A: The different states of matter are solid, liquid, and gas.
18. Q: Give an example of a solid.
A: Wood is an example of a solid.
19. Q: State the characteristics of a liquid.
A: Liquids have a definite volume but no definite shape.
20. Q: Name a liquid that is commonly used for cooking.
A: Water is a common liquid used for cooking.
21. Q: Define gas.
A: Gas is a state of matter that has neither a definite shape nor a definite volume.
22. Q: Name a gas that is present in the air we breathe.
A: Oxygen is one of the gases present in the air we breathe.
23. Q: What is a solute?
A: A solute is a substance that is dissolved in a solvent to form a solution.
24. Q: Define solvent.
A: A solvent is a substance that dissolves a solute to form a solution.
25. Q: Name the universal solvent.
A: Water is often referred to as the universal solvent.
26. Q: What is a solution?
A: A solution is a homogeneous mixture of two or more substances.
27. Q: Define mixture.
A: A mixture is the combination of two or more substances that are not chemically
bound
together.
28. Q: Give an example of a mixture.
A: Saltwater is an example of a mixture.
29. Q: What is a natural change?
A: A natural change is a change that occurs on its own without any external
intervention.
30. Q: Name a natural change that takes place due to the weather.
A: The formation of dew on leaves in the morning is an example of a natural change.
31. Q: What is a man-made change?
A: A man-made change is a change that is caused or influenced by human activities.
32. Q: Give an example of a man-made change.
A: Constructing buildings is an example of a man-made change.
33. Q: What is weathering?
A: Weathering refers to the breaking down or wearing away of rocks and other
materials
on the Earth's surface.
34. Q: Define erosion.
A: Erosion is the process of transporting weathered materials from one place to
another.
35. Q: Name a natural agent of erosion.
A: Water is a natural agent of erosion.
36. Q: State the importance of recycling.
A: Recycling helps in conserving natural resources and reducing waste.
37. Q: What are fossils?
A: Fossils are the preserved remains or traces of organisms that lived in the past.
38. Q: Why are fossils important?
A: Fossils provide evidence of past life forms and help us understand the history of
the
Earth.
39. Q: Define composting.
A: Composting is the process of converting organic waste into nutrient-rich compost,
which can be used as a natural fertilizer.
40. Q: Explain the concept of reduce, reuse, and recycle.
A: Reduce, reuse, and recycle are three strategies to minimize waste and protect the
environment.
41. Q: What is pollution?
A: Pollution refers to the introduction of harmful substances or contaminants into
the
environment, causing adverse effects.
42. Q: Name a type of pollution caused by vehicles.
A: Air pollution is often caused by vehicle emissions.
43. Q: What are greenhouse gases?
A: Greenhouse gases are gases in the Earth's atmosphere that trap heat and
contribute to
climate change.
44. Q: State the consequences of deforestation.
A: Deforestation leads to loss of biodiversity, soil erosion, and climate change.
45. Q: How can we conserve water at home?
A: We can conserve water at home by fixing leaky faucets, using water-efficient
appliances, and taking shorter showers.
46. Q: What is renewable energy?
A: Renewable energy is energy generated from sources that are continually
replenished,
such as sunlight and wind.
47. Q: Explain the role of the ozone layer.
A: The ozone layer protects the Earth from harmful ultraviolet (UV) radiation from
the
sun.
48. Q: What is global warming?
A: Global warming refers to the long-term increase in Earth's average surface
temperature, primarily due to human activities.
49. Q: Define climate change.
A: Climate change refers to long-term changes in temperature, precipitation
patterns,
and other aspects of the Earth's climate system.
50. Q: What are some ways to reduce carbon footprint?
A: Reducing reliance on fossil fuels, using energy-efficient appliances, and
practicing
sustainable transportation are some ways to reduce carbon footprint.
Chapter 7 Getting to Know Plant's
1. What is photosynthesis?
Solution: Photosynthesis is the process by which plants convert sunlight, carbon
dioxide, and water into glucose and oxygen.
2. Name the green pigment found in plants.
Solution: The green pigment found in plants is chlorophyll.
3. What is the main function of roots in plants?
Solution: The main function of roots in plants is to absorb water and nutrients from
the soil and anchor the plant in the ground.
4. Define germination.
Solution: Germination is the process by which a seed sprouts and begins to grow into
a new plant.
5. Give an example of a plant with fibrous roots.
Solution: Grass is an example of a plant with fibrous roots.
6. What is the role of leaves in plants?
Solution: Leaves are responsible for the process of photosynthesis and help in the
exchange of gases with the atmosphere.
7. Define pollination.
Solution: Pollination is the transfer of pollen from the male reproductive part
(anther) to the female reproductive part (stigma) of a flower.
8. What are the two main parts of a flower?
Solution: The two main parts of a flower are the pistil (female reproductive part)
and stamen (male reproductive part).
9. Describe the process of fertilization in plants.
Solution: Fertilization in plants occurs when pollen from the stamen reaches the
stigma of the pistil, leading to the formation of seeds.
10. What is the purpose of a fruit in a plant?
Solution: The purpose of a fruit in a plant is to protect the seeds and aid in their
dispersal.
11. What are the three main functions of stems in plants?
Solution: The three main functions of stems in plants are to provide support,
transport water and nutrients, and store food.
12. Name three plants that reproduce by vegetative propagation.
Solution: Some plants that reproduce by vegetative propagation are potato, onion,
and banana.
13. Explain how plants adapt to different habitats.
Solution: Plants adapt to different habitats by modifying their roots, stems,
leaves, and reproductive structures to survive in various environmental conditions.
14. What is the difference between a herb and a shrub?
Solution: A herb is a small, non-woody plant, whereas a shrub is a woody plant with
multiple stems.
15. How do carnivorous plants obtain nutrients?
Solution: Carnivorous plants obtain nutrients by trapping and digesting small
insects or other organisms.
16. Name two plants that show thigmotropism.
Solution: Some plants that show thigmotropism are the money plant and the
touch-me-not plant.
17. Define phototropism.
Solution: Phototropism is the growth or movement of a plant in response to light.
18. Differentiate between insect-pollinated and wind-pollinated flowers.
Solution: Insect-pollinated flowers have bright colors, strong fragrance, and
produce nectar, while wind-pollinated flowers are small, inconspicuous, and
produce large quantities of pollen.
19. Explain the process of transpiration in plants.
Solution: Transpiration is the loss of water vapor from plant leaves through tiny
pores called stomata.
20. Why are plants considered producers in the food chain?
Solution: Plants are considered producers because they can convert sunlight into
food through photosynthesis.
21. Define asexual reproduction in plants.
Solution: Asexual reproduction in plants is the process of producing offspring
without the involvement of seeds or spores.
22. What is the function of thorns in plants?
Solution: Thorns in plants protect them from herbivores and help conserve water.
23. State two methods of seed dispersal.
Solution: Two methods of seed dispersal are wind dispersal and animal dispersal.
24. Explain the importance of flowers in plant reproduction.
Solution: Flowers are essential for plant reproduction as they attract pollinators
and help in the transfer of pollen for fertilization.
25. What is the difference between taproots and fibrous roots?
Solution: Taproots are thick and have a prominent main root, while fibrous roots are
thin and spread out to form a dense network.
26. Describe the structure of a leaf.
Solution: A leaf typically consists of a flat blade, a petiole, and veins that
transport water, nutrients, and sugars.
27. Identify two types of parasitic plants.
Solution: Two types of parasitic plants are mistletoe and dodder.
28. Explain why leaves change color in autumn.
Solution: Leaves change color in autumn due to the breakdown of chlorophyll,
revealing other pigments present in the leaves.
29. How do plants obtain nitrogen for growth?
Solution: Plants obtain nitrogen for growth from the soil through their roots, often
in the form of nitrates.
30. What is the purpose of the sepals in a flower?
Solution: The sepals in a flower protect the flower bud before it blooms.
31. Define hydrotropism.
Solution: Hydrotropism is the growth or movement of a plant in response to water.
32. Give an example of a plant that reproduces by spores.
Solution: Ferns are an example of plants that reproduce by spores.
33. Explain the role of auxins in plant growth.
Solution: Auxins are plant hormones that promote elongation of stems, regulate
phototropism, and control apical dominance.
34. How do desert plants conserve water?
Solution: Desert plants conserve water by having thick, waxy cuticles, reducing the
number of stomata, and having long taproots.
35. Name three climbers or creepers.
Solution: Ivy, cucumber, and grapevine are examples of climbers or creepers.
36. What is the function of the ovary in a flower?
Solution: The ovary in a flower protects and contains the ovules, which develop into
seeds after fertilization.
37. Identify two plants that reproduce through bulbs.
Solution: Two plants that reproduce through bulbs are tulips and lilies.
38. Explain the process of nitrogen fixation in plants.
Solution: Nitrogen fixation is the conversion of atmospheric nitrogen into a usable
form by certain bacteria, which can then be absorbed by plants.
39. How do plants adapt to live in aquatic habitats?
Solution: Plants in aquatic habitats have adaptations like hollow stems, floating
leaves, and well-developed air sacs to help with buoyancy.
40. What is the function of the stigma in a flower?
Solution: The stigma in a flower receives pollen grains for fertilization.
41. Differentiate between herbs and trees.
Solution: Herbs are smaller, non-woody plants with soft stems, while trees are
larger, woody plants with hard stems.
42. Explain how plants are involved in the carbon cycle.
Solution: Plants play a crucial role in the carbon cycle by absorbing carbon dioxide
during photosynthesis and releasing oxygen into the atmosphere.
43. Describe the role of the petal in a flower.
Solution: The petals in a flower are often brightly colored and scented, attracting
pollinators for effective pollination.
44. Name three plants that store food in their stems.
Solution: Some plants that store food in their stems are potato, ginger, and cactus.
45. Explain the process of nastic movements in plants.
Solution: Nastic movements in plants are non-directional movements caused by changes
in turgor pressure in response to stimuli like touch or light.
46. What is the function of the anther in a flower?
Solution: The anther in a flower produces pollen grains, which contain the male
gametes required for fertilization.
47. Differentiate between a taproot and a fibrous root system.
Solution: A taproot system consists of one main root with smaller lateral roots,
while a fibrous root system consists of numerous thin roots that spread out.
48. What is the purpose of leaf veins?
Solution: Leaf veins transport water, minerals, and sugars within a leaf and provide
structural support.
49. Define dormancy in plants.
Solution: Dormancy in plants is a state of reduced activity or growth during
unfavorable conditions, such as winter or drought.
50. Explain the process of self-pollination in plants.
Solution: Self-pollination in plants occurs when pollen from the anther of a flower
is transferred to the stigma of the same flower or another flower on the same
plant.
Chapter 8 Body Movements
1. What are the two types of movements in our body?
Solution: The two types of movements in our body are voluntary and involuntary
movements.
2. What are voluntary movements?
Solution: Voluntary movements are those movements that we can control consciously,
such as walking or writing.
3. What are involuntary movements?
Solution: Involuntary movements are those movements that we do not have control
over, such as the beating of the heart or blinking of the eyes.
4. Which type of muscle is responsible for voluntary movements?
Solution: Voluntary movements are controlled by skeletal muscles.
5. Name the three types of joints found in our body.
Solution: The three types of joints are immovable joints, slightly movable joints,
and freely movable joints.
6. Give an example of an immovable joint in our body.
Solution: The skull is an example of an immovable joint in our body.
7. What are hinge joints?
Solution: Hinge joints allow movement in one direction, like a door hinge. An
example is the knee joint.
8. Name two hinge joints in our body.
Solution: The elbow and knee joints are examples of hinge joints.
9. Which joint is responsible for the movement of the head?
Solution: The neck joint is responsible for the movement of the head.
10. What do ball and socket joints allow?
Solution: Ball and socket joints allow movement in all directions. The shoulder and
hip joints are examples.
11. What are fixed pivot joints?
Solution: Fixed pivot joints allow rotating movement around an axis, like the
rotation of the head.
12. Mention one example of a fixed pivot joint.
Solution: The joint between the atlas and axis bones in our neck is an example of a
fixed pivot joint.
13. How many bones are there in the human body?
Solution: There are a total of 206 bones in the human body.
14. What is the smallest bone in our body?
Solution: The stapes bone in the middle ear is the smallest bone in our body.
15. What is the largest bone in our body?
Solution: The femur bone in the thigh is the largest bone in our body.
16. What is the purpose of ligaments?
Solution: Ligaments are tough, fibrous tissues that connect bones and hold them
together, providing stability to the joints.
17. What is the purpose of tendons?
Solution: Tendons are strong, fibrous tissues that connect muscles to bones,
enabling movement.
18. What is the importance of exercise for our muscles and joints?
Solution: Cartilage acts as a cushion between the bones at the joints, preventing
them from rubbing against each other.
20. What is the role of synovial fluid in the joints?
Solution: Synovial fluid lubricates the joints, reducing friction between the bones
during movement.
21. Define locomotion.
Solution: Locomotion is the ability to move from one place to another, either by
walking, running, crawling, or swimming.
22. What is the difference between walking and running?
Solution: Walking is a slow-paced movement where one foot is always in contact with
the ground, while running is a faster movement where both feet
momentarily leave the ground.
23. How do snakes move?
Solution: Snakes move by using their muscles to contract and expand their body,
allowing them to slither on the ground.
24. What is the significance of the backbone in our body movements?
Solution: The backbone, or the vertebral column, provides support and flexibility to
our body. It allows us to bend, twist, and perform various movements.
25. What is the purpose of reflex action in our body?
Solution: Reflex actions are involuntary movements that help in self-protection and
quick response to external stimuli, such as withdrawing a hand from a hot
object.
26. Define posture.
Solution: Posture refers to the position in which we hold our body while sitting,
standing, or lying down.
27. Why is it important to maintain good posture?
Solution: Good posture helps in preventing strain on muscles, joints, and ligaments,
reducing the risk of musculoskeletal disorders.
28. What can we do to maintain good posture?
Solution: To maintain good posture, we should sit and stand straight, avoid
slouching, and use ergonomically designed furniture.
29. How can we take care of our bones and muscles?
Solution: We can take care of our bones and muscles by eating a balanced diet rich
in calcium and proteins, exercising regularly, and avoiding injuries.
30. What is osteoporosis?
Solution: Osteoporosis is a condition characterized by the weakening of bones,
making them fragile and more prone to fractures.
31. Explain the importance of stretching before exercise.
Solution: Stretching before exercise helps in warming up the muscles, increasing
flexibility, and preventing injuries.
32. What are the different types of body movements?
Solution: The different types of body movements include bending, stretching,
twisting, turning, and lifting.
33. What is the purpose of warm-up exercises?
Solution: Warm-up exercises prepare our muscles and joints for physical activity,
increasing blood flow and flexibility.
34. Define coordination.
Solution: Coordination is the ability to use different body parts smoothly and
efficiently to achieve a goal or perform a task.
35. How can we improve our coordination skills?
Solution: Coordination skills can be improved through regular practice of activities
that involve hand-eye coordination, such as playing sports or musical
instruments.
36. What are the different types of sports that require good coordination?
Solution: Sports such as basketball, football, tennis, and gymnastics require good
coordination of various body movements.
37. Explain the term "range of motion."
Solution: Range of motion refers to the full movement potential of a joint or a
group of joints. It measures how much a joint can move in different directions.
38. How can we improve our range of motion?
Solution: Regular stretching exercises, yoga, and physical therapy can help improve
range of motion.
39. What is the role of sensory receptors in body movements?
Solution: Sensory receptors provide information to our brain about changes in body
position, enabling us to maintain balance and make coordinated movements.
40. What are the advantages of regular physical activity?
Solution: Regular physical activity improves cardiovascular health, builds strength
and endurance, enhances flexibility, and promotes overall well-being.
41. Explain the term "fulcrum" in the context of body movements.
Solution: Fulcrum refers to the point around which a lever pivots or rotates. It
plays a crucial role in generating movement in our body.
42. What are antagonistic muscles?
Solution: Antagonistic muscles are pairs of muscles that work in opposition to each
other. When one muscle contracts, the other relaxes.
43. Give an example of antagonistic muscles and their movement.
Solution: Biceps and triceps are antagonistic muscles. When the biceps contract, the
arm flexes, and when the triceps contract, the arm extends.
44. How do fish move in water?
Solution: Fish move in water by using their muscles to create a wave-like motion of
their bodies and fins, propelling them forward.
45. Define respiration.
Solution: Respiration is the process of taking in oxygen from the environment and
expelling carbon dioxide from the body.
46. How does respiration relate to body movements?
Solution: Body movements, such as breathing, are essential for respiration.
Breathing involves the coordinated movement of the ribcage and diaphragm.
47. What are the effects of a sedentary lifestyle on body movements?
Solution: A sedentary lifestyle can lead to weakened muscles, stiffness in joints,
poor posture, and decreased range of motion.
48. How does age affect body movements?
Solution: With age, muscles and joints may become weaker and stiffer, reducing
flexibility and range of motion. Regular exercise can help mitigate these
effects.
49. Describe the role of exercise in maintaining a healthy musculoskeletal
system.
Solution: Exercise strengthens muscles, improves joint flexibility, enhances bone
density, and promotes overall bone and joint health.
50. What are the precautions one should take to prevent injuries during physical
activity?
Solution: To prevent injuries, one should warm up before exercise, use proper
equipment and protective gear, maintain correct form and posture, and avoid
overexertion.
Chapter 9 The Living Organisms and Their Surroundings
1. Question: What is the meaning of the term 'habitat'?
Solution: Habitat refers to the natural environment where an organism lives and
obtains the necessary resources to survive.
2. Question: Define the term 'adaptation'.
Solution: Adaptation is the process by which organisms become better suited to their
environment through inherited traits or behaviors.
3. Question: Name three different habitats.
Solution: Forests, deserts, and oceans are three different types of habitats.
4. Question: What are the components of an ecosystem?
Solution: The components of an ecosystem include living organisms, their physical
surroundings, and the interactions between them.
5. Question: Give an example of a producer in an ecosystem.
Solution: Plants are examples of producers as they produce their food through
photosynthesis.
6. Question: How do consumers obtain their food?
Solution: Consumers obtain their food by consuming other organisms.
7. Question: Define decomposers and provide an example.
Solution: Decomposers are organisms that break down dead organic matter. Examples
include bacteria and fungi.
8. Question: Explain the term 'food chain'.
Solution: A food chain is a sequence of organisms showing the transfer of energy
through feeding relationships.
9. Question: Differentiate between herbivores and carnivores.
Solution: Herbivores are animals that only eat plants, whereas carnivores are
animals that feed on other animals.
10. Question: What is a food web?
Solution: A food web is a complex network of interconnected food chains that shows
the flow of energy in an ecosystem.
11. Question: Name two abiotic components of an ecosystem.
Solution: Sunlight and air are two examples of abiotic components in an ecosystem.
12. Question: Explain the term 'biotic factors'.
Solution: Biotic factors are living components of an ecosystem, including plants,
animals, and microorganisms.
13. Question: What is the role of decomposers in an ecosystem?
Solution: Decomposers play a vital role in recycling nutrients by breaking down dead
organic matter and returning the nutrients to the soil.
14. Question: Define the term 'predator'.
Solution: A predator refers to an animal that hunts, kills, and feeds on other
animals.
15. Question: What are the different levels of organization in an ecosystem?
Solution: The levels of organization in an ecosystem are organism, population,
community, and ecosystem.
16. Question: Describe the greenhouse effect.
Solution: The greenhouse effect is the process by which certain gases in the Earth's
atmosphere trap heat, resulting in a warming effect.
17. Question: Name three types of consumers in a food chain.
Solution: Herbivores, carnivores, and omnivores are three types of consumers in a
food chain.
18. Question: What do you understand by the term 'carnivorous plants'?
Solution: Carnivorous plants are plants that can trap, kill, and digest small
animals to obtain nutrients.
19. Question: Differentiate between food chain and food web.
Solution: A food chain is a linear sequence of organisms, whereas a food web is a
complex network of interconnected food chains.
20. Question: What is the role of decomposers in nutrient cycling?
Solution: Decomposers break down organic matter, releasing nutrients back into the
soil, which can be used by plants for growth.
21. Question: Define the term 'biome'.
Solution: A biome is a large geographical area on Earth characterized by distinctive
climate, vegetation, and animal life.
22. Question: Give an example of a freshwater ecosystem.
Solution: Lakes, ponds, and rivers are examples of freshwater ecosystems.
23. Question: Name two producers found in an aquatic ecosystem.
Solution: Algae and phytoplankton are two examples of producers found in aquatic
ecosystems.
24. Question: Explain the term 'niche' in an ecosystem.
Solution: Niche refers to the specific role or job an organism has within its
habitat, including its interactions with other organisms and its use of resources.
25. Question: Describe the process of photosynthesis.
Solution: Photosynthesis is the process by which plants use sunlight, carbon
dioxide, and water to produce glucose (food) and release oxygen.
26. Question: What do you mean by 'microhabitats'?
Solution: Microhabitats are small, specialized habitats within a larger habitat,
supporting specific communities of organisms.
27. Question: What are the three types of symbiotic relationships?
Solution: The three types of symbiotic relationships are mutualism, commensalism,
and parasitism.
28. Question: Define the term 'ecological succession'.
Solution: Ecological succession refers to the gradual process of change and
development in an ecosystem over time.
29. Question: Name two examples of commensalism.
Solution: One example of commensalism is the relationship between a barnacle and a
whale. The barnacle benefits, while the whale is unaffected.
30. Question: What is the difference between a habitat and a niche?
Solution: Habitat is the physical location where an organism lives, while niche
refers to the organism's specific role and interactions within its habitat.
31. Question: What is meant by the term 'extinction'?
Solution: Extinction refers to the complete eradication of a species from the Earth,
resulting in no living individuals remaining.
32. Question: How does deforestation affect the environment?
Solution: Deforestation leads to habitat destruction, loss of biodiversity, climate
change, and soil erosion.
33. Question: Explain the term 'invasive species'.
Solution: Invasive species are non-native organisms that rapidly spread and disrupt
the balance of an ecosystem, often causing harm to native species.
34. Question: What are the major causes of air pollution?
Solution: The major causes of air pollution include industrial emissions, vehicle
exhaust, and the burning of fossil fuels.
35. Question: What is the importance of conservation?
Solution: Conservation is vital for preserving biodiversity, maintaining ecosystem
services, and ensuring a sustainable future for all living organisms.
36. Question: Define the term 'biodegradable'.
Solution: Biodegradable substances are those that can be broken down naturally by
living organisms, ultimately becoming part of the environment.
37. Question: How do human activities contribute to water pollution?
Solution: Human activities such as improper waste disposal, industrial discharge,
and agricultural runoff can contaminate water bodies, leading to water
pollution.
38. Question: Explain the term 'pollination'.
Solution: Pollination is the transfer of pollen from the male reproductive part
(stamen) to the female reproductive part (pistil) of a flower, leading to
fertilization and seed production.
39. Question: How does overfishing impact marine ecosystems?
Solution: Overfishing disrupts the balance in marine ecosystems, depleting fish
populations, and leading to wide-ranging ecological consequences.
40. Question: Define the term 'climate change'.
Solution: Climate change refers to long-term alterations in temperature patterns,
rainfall, and other weather conditions, primarily caused by human activities.
41. Question: What is the role of wetlands in an ecosystem?
Solution: Wetlands play a crucial role in water purification, flood control, and
providing habitat for a variety of plant and animal species.
42. Question: Name two endangered species.
Solution: Two examples of endangered species are the giant panda and the black
rhinoceros.
43. Question: How does pollution affect the ozone layer?
Solution: Certain pollutants, such as chlorofluorocarbons (CFCs), can cause the
depletion of the ozone layer, resulting in increased UV radiation reaching the
Earth's surface.
44. Question: How can individuals contribute to biodiversity conservation?
Solution: Individuals can contribute to biodiversity conservation by supporting
sustainable practices, participating in conservation projects, and raising
awareness about the importance of biodiversity.
45. Question: What is biomagnification?
Solution: Biomagnification refers to the process where the concentration of
certain
harmful substances increases as it moves up the food chain.
46. Question: How does sound pollution affect wildlife?
Solution: Sound pollution disrupts animal communication, interferes with mating
and
feeding patterns, and can cause stress or even death in certain species.
47. Question: Explain the term 'desertification'.
Solution: Desertification is the process by which fertile land becomes desert
due to
various factors like drought, overgrazing, and deforestation.
48. Question: What is the role of a bioindicator in assessing environmental
health?
Solution: Bioindicators are organisms or species whose health and population
dynamics reflect the quality of the environment, helping scientists assess
environmental health.
49. Question: How do natural disasters affect ecosystems?
Solution: Natural disasters can cause the destruction of habitats, loss of
species,
disruption of ecological processes, and long-term impacts on ecosystem
dynamics.
50. Question: Define the term 'sustainable development'.
Solution: Sustainable development refers to meeting present needs without
compromising the ability of future generations to meet their own needs,
considering social, economic, and environmental aspects.
Chapter 10 Motion and Measurement of Distances
1. Question: What is motion?
Solution: Motion is when an object changes its position with time.
2. Question: What is distance?
Solution: Distance is the total path traveled by an object.
3. Question: What is speed?
Solution: Speed is the distance traveled by an object per unit of time.
4. Question: Define uniform motion.
Solution: Uniform motion is when an object covers equal distances in equal
intervals of time.
5. Question: What is the formula to calculate speed?
Solution: Speed = Distance/Time
6. Question: What are the SI units of distance, time, and speed?
Solution: Distance - meters (m), Time - seconds (s), Speed - meters per second
(m/s)
7. Question: What is the difference between speed and velocity?
Solution: Speed is the measure of how fast an object is moving, whereas velocity
is speed in a given direction.
8. Question: What is meant by the term 'motion in a straight line'?
Solution: Motion in a straight line refers to the movement of an object only in
one direction.
9. Question: What are the types of motion?
Solution: The types of motion are rectilinear, circular, and periodic motion.
10. Question: What is the difference between distance and displacement?
Solution: Distance refers to the total path traveled, whereas displacement is
the shortest distance between the initial and final position.
11. Question: Define acceleration.
Solution: Acceleration is the change in velocity of an object per unit time.
12. Question: What is the formula to calculate acceleration?
Solution: Acceleration = (Final velocity - Initial velocity) / Time
13. Question: What is the unit of acceleration?
Solution: The unit of acceleration is meters per second squared (m/s²).
14. Question: Explain the term 'balanced forces.'
Solution: Balanced forces are forces that are equal in magnitude and
opposite in
direction, resulting in no change in motion.
15. Question: Can an object be accelerated without changing its speed?
Solution: Yes, an object can be accelerated without changing its speed by
changing its direction.
16. Question: What do you mean by a 'speed-time graph'?
Solution: A speed-time graph shows how an object's speed changes with time.
17. Question: How can you calculate the average speed from a speed-time
graph?
Solution: The average speed can be calculated as the total distance covered
divided by the total time taken.
18. Question: What is the difference between distance-time and
speed-time
graphs?
Solution: A distance-time graph shows how the distance changes with time,
while
a speed-time graph shows how the speed changes with time.
19. Question: State three examples where uniform motion is observed in
daily
life.
Solution: Examples include a car moving along a straight road at a constant
speed, the Earth revolving around the Sun, and a pendulum swinging back and
forth.
20. Question: Why is it necessary to use a standard unit for
measurement?
Solution: Using a standard unit ensures consistency and allows for easy
comparison between measurements.
21. Question: Define the term 'mechanical stopwatch.'
Solution: A mechanical stopwatch is a device used to measure time intervals
accurately.
22. Question: How can we increase the speed of an object?
Solution: To increase the speed of an object, we can apply a force in the
direction of motion.
23. Question: Explain the term 'stoppage.'
Solution: Stoppage refers to the act of coming to a halt or stopping the
motion
of an object.
24. Question: What is the difference between motion along a straight
line and
motion in a plane?
Solution: Motion along a straight line refers to motion in only one
dimension,
whereas motion in a plane occurs in two dimensions.
25. Question: How can we represent motion graphically?
Solution: We can represent motion graphically using distance-time graphs or
speed-time graphs.
26. Question: What is the difference between speed and average speed?
Solution: Speed refers to how fast an object is moving at a particular
instant,
while average speed is the total distance traveled divided by the total time
taken.
27. Question: Explain how to convert between km/h and m/s.
Solution: To convert from km/h to m/s, divide the speed by 3.6. To convert
from
m/s to km/h, multiply the speed by 3.6.
28. Question: How can we measure distances using a ruler?
Solution: We can measure distances using a ruler by placing it along the
length
of the object and reading the value where it ends.
29. Question: Define the term 'speedometer.'
Solution: A speedometer is an instrument used to measure and display the
speed
of a vehicle.
30. Question: What is the importance of relative motion?
Solution: Relative motion allows us to understand the motion of one object
with
respect to another object.
31. Question: State Archimedes' principle.
Solution: Archimedes' principle states that an object immersed in a fluid
experiences an upward buoyant force equal to the weight of the fluid
displaced.
32. Question: How can we measure time accurately using a stopwatch?
Solution: We can measure time accurately using a stopwatch by pressing the
start
button when the motion begins and pressing the stop button when it ends.
33. Question: Explain the term 'speed limit.'
Solution: Speed limit refers to the maximum allowable speed at which a
vehicle
can travel on a particular road.
34. Question: What is the relationship between distance, speed, and
time?
Solution: The relationship between distance, speed, and time is given by the
equation: Distance = Speed × Time.
35. Question: How can we calculate the distance covered by a moving
object in a
given time interval?
Solution: To calculate the distance covered, multiply the speed of the
object by
the time taken.
36. Question: What is the effect of friction on motion?
Solution: Friction opposes the motion of objects and tends to decrease the
speed.
37. Question: State Newton's first law of motion.
Solution: Newton's first law of motion states that an object at rest will
remain
at rest, and an object in motion will continue to move with a constant
velocity
unless acted upon by an external force.
38. Question: What is the difference between instantaneous speed and
average
speed?
Solution: Instantaneous speed refers to the speed of an object at a
particular
instant, while average speed is calculated over a specified time interval.
39. Question: Explain the term 'positive acceleration.'
Solution: Positive acceleration refers to an increase in velocity over time.
40. Question: How can we measure the speed of a moving object?
Solution: We can measure the speed of a moving object by dividing the
distance
traveled by the time taken.
41. Question: Define the term 'elapsed time.'
Solution: Elapsed time refers to the total time taken from the start to the
end
of a particular event or motion.
42. Question: How can we determine the direction of motion using a
velocity-time
graph?
Solution: The direction of motion can be determined by the positive or
negative
slope of the velocity-time graph.
43. Question: What is the difference between constant speed and average
speed?
Solution: Constant speed refers to a consistent rate of motion, while
average
speed is the total distance covered divided by the total time taken.
44. Question: Explain the term 'deceleration.'
Solution: Deceleration refers to the rate at which an object slows down or
decreases in speed.
45. Question: What is the difference between speed and distance covered?
Solution: Speed refers to the rate of motion, while distance covered is the
total path traveled.
46. Question: How does the distance between two objects affect the force
of
attraction between them?
Solution: The force of attraction between two objects decreases as the
distance
between them increases.
47. Question: State the principle of conservation of momentum.
Solution: The principle of conservation of momentum states that the total
momentum of a system remains constant when no external forces are acting on
it.
48. Question: Explain what stopping distance is.
Solution: Stopping distance is the total distance traveled by a vehicle from
the
time the brakes are applied until it comes to a complete stop.
49. Question: Define 'average velocity.'
Solution: Average velocity refers to the displacement of an object divided
by
the total time taken.
50. Question: How can we calculate the displacement of a moving object?
Solution: Displacement can be calculated by subtracting the initial position
from the final position of the object.
Chapter 11 Light Shadows and Reflections
Question 1:
What is light?
Solution:
Light is a form of energy that enables us to see objects around us. It
travels in straight lines.
Question 2:
Which objects can produce light?
Solution:
Objects that can produce light are called luminous objects. Examples
include
the sun, electric bulbs, and candles.
Question 3:
What do you mean by opaque objects?
Solution:
Opaque objects do not allow light to pass through them. They form
shadows
when light falls on them.
Question 4:
Give an example of an opaque object.
Solution:
A wooden block is an example of an opaque object because it doesn't
allow
light to pass through it.
Question 5:
Define reflection.
Solution:
Reflection is the bouncing back of light when it strikes a surface and
does
not pass through it.
Question 6:
What is a shadow?
Solution:
A shadow is a dark area formed when an object blocks the path of light.
Question 7:
What causes a shadow to appear?
Solution:
A shadow appears when an object blocks the path of light.
Question 8:
What happens to the size of the shadow when the distance between the
object
and the screen increases?
Solution:
When the distance between the object and the screen increases, the size
of
the shadow decreases.
Question 9:
What is the angle of incidence?
Solution:
The angle of incidence is the angle between the incident ray and the
normal
drawn at the point of incidence.
Question 10:
When does refraction of light occur?
Solution:
Refraction of light occurs when light passes from one transparent medium
to
another, causing it to change direction.
Question 11:
What is a lens?
Solution:
A lens is a transparent object with curved surfaces that refracts light
and
focuses it to form images.
Question 12:
How many types of lenses are there?
Solution:
There are two types of lenses: convex lenses and concave lenses.
Question 13:
What is the difference between a convex and a concave lens?
Solution:
A convex lens is thicker at the center and thinner at the edges, while a
concave lens is thinner at the center and thicker at the edges.
Question 14:
What happens to the direction of light when it passes through a
convex lens?
Solution:
When light passes through a convex lens, it converges or comes together
at a
point called the focus.
Question 15:
What is the focal length of a lens?
Solution:
The focal length of a lens is the distance between the lens and its
focus
when the light is parallel to the principal axis.
Question 16:
What is a spectrum?
Solution:
A spectrum is a band of colors formed when white light is passed through
a
prism or a raindrop.
Question 17:
What are the colors of the spectrum in order?
Solution:
The colors of the spectrum in order are red, orange, yellow, green,
blue,
indigo, and violet (ROYGBIV).
Question 18:
What is the primary function of the human eye?
Solution:
The primary function of the human eye is to detect and focus light to
form
images on the retina.
Question 19:
What is the cornea?
Solution:
The cornea is the transparent front part of the eye that helps in
focusing
light.
Question 20:
What is the retina?
Solution:
The retina is a layer at the back of the eye that contains
light-sensitive
cells called rods and cones.
Question 21:
Which part of the eye helps us see in dim light?
Solution:
The rod cells present in the retina help us see in dim light.
Question 22:
Which part of the eye helps us see colors?
Solution:
The cone cells present in the retina help us see colors.
Question 23:
What is dispersion of light?
Solution:
Dispersion of light is the process where white light splits into its
component colors when passed through a prism.
Question 24:
What is the angle of refraction?
Solution:
The angle of refraction is the angle between the refracted ray and the
normal drawn at the point of refraction.
Question 25:
Why does a straight stick appear bent when placed in a glass of
water?
Solution:
When light passes from air to water, it refracts and bends. This causes
the
straight stick to appear bent.
Question 26:
What does the law of reflection state?
Solution:
The law of reflection states that the angle of incidence is equal to the
angle of reflection.
Question 27:
Why do objects appear smaller when placed further away?
Solution:
Objects appear smaller when placed further away because their image
formed
on the retina becomes smaller.
Question 28:
Why can't we see in the dark?
Solution:
We cannot see in the dark because there is no light present that can be
reflected by objects to reach our eyes.
Question 29:
What is a periscope used for?
Solution:
A periscope is an optical instrument that uses mirrors to see objects
that
are not in direct line of sight.
Question 30:
Why do we see colors in the sky during a rainbow?
Solution:
We see colors in the sky during a rainbow because sunlight passes
through
raindrops and gets dispersed, forming a spectrum of colors.
Question 31:
How does a magnifying glass work?
Solution:
A magnifying glass works by using a convex lens to refract light,
allowing
us to see objects magnified and in greater detail.
Question 32:
Which type of lens is used in a magnifying glass?
Solution:
A convex lens is used in a magnifying glass.
Question 33:
What is the purpose of a sunshade on a car's windshield?
Solution:
A sunshade on a car's windshield reduces the amount of light entering
the
car, making it more comfortable and reducing glare.
Question 34:
How does a prism work?
Solution:
A prism works by refracting (bending) light at different angles, causing
the
white light to split into its component colors.
Question 35:
Why does an object immersed in water appear to be lifted up?
Solution:
When light passes from water to air, it refracts and bends away from the
normal. This makes objects appear slightly lifted up.
Question 36:
What is the speed of light?
Solution:
The speed of light is approximately 299,792 kilometers per second (km/s) in
a vacuum.
Question 37:
What is the difference between a shadow and a reflection?
Solution:
A shadow is the absence of light due to an object blocking it, while a
reflection is the bouncing back of light when it strikes a surface.
Question 38:
What is total internal reflection?
Solution:
Total internal reflection occurs when light traveling from a denser medium
to a less dense medium is completely reflected back.
Question 39:
What is a virtual image?
Solution:
A virtual image is an image that cannot be formed on a screen. It can only
be seen when looking through a lens or a mirror.
Question 40:
What is the purpose of a convex mirror?
Solution:
A convex mirror is used to provide a wider field of view, making it helpful
in environments like parking lots and blind spots.
Question 41:
What is the purpose of a concave mirror?
Solution:
A concave mirror is often used to focus light onto a specific point, making
it useful in devices like telescopes and headlights.
Question 42:
Why does a swimming pool appear shallower than it actually is?
Solution:
When light passes from water into air, it refracts and bends away from the
normal. This makes objects in water appear closer to the surface than they
actually
are.
Question 43:
How can light energy be converted into electrical energy?
Solution:
Light energy can be converted into electrical energy using devices like
solar panels, which capture sunlight and convert it into electricity.
Question 44:
What is the purpose of a lens in a camera?
Solution:
The lens in a camera helps in focusing light onto the film or image sensor,
allowing the formation of a clear and detailed image.
Question 45:
Why does a mirage appear on a hot day?
Solution:
A mirage appears on a hot day due to the refraction of light caused by the
varying densities of air layers near the ground, creating an optical
illusion of water.
Question 46:
What is the meaning of the term "3D" in films?
Solution:
The term "3D" in films refers to three-dimensional visuals that create an
illusion of depth, making objects and scenes appear real and lifelike.
Question 47:
Why does a pencil placed in a glass of water appear broken?
Solution:
When light passes from water to air, it refracts and bends away from the
normal. This refraction causes the pencil to appear broken at the water-air
interface.
Question 48:
What is the purpose of a magnifying mirror?
Solution:
A magnifying mirror is used to see close-up details of objects, making it
useful for activities like applying makeup or examining small objects.
Question 49:
Why do we see our reflection in a mirror?
Solution:
We see our reflection in a mirror because light rays bounce off the mirror's
surface and reflect back into our eyes, allowing us to see ourselves.
Question 50:
How does a rainbow form?
Solution:
A rainbow forms when sunlight passes through raindrops and undergoes
dispersion. Each raindrop acts as a prism, splitting the light into its
component colors
and forming an arc of colors in the sky.
Chapter 12 Electricity and Circuits
Q: What is electricity?
A: Electricity is the flow of electric charges.
Q: What is an electric circuit?
A: An electric circuit is a closed loop through which electricity can flow.
Q: What is an electric current?
A: Electric current is the flow of electric charges in a circuit.
Q: Define conductor and give an example.
A: A conductor is a material that allows the flow of electricity. Example:
Copper.
Q: Define insulator and give an example.
A: An insulator is a material that does not allow the flow of electricity.
Example: Rubber.
Q: What is a switch?
A: A switch is a device used to break or complete a circuit.
Q: What is a bulb?
A: A bulb is a device that converts electrical energy into light.
Q: What is a battery?
A: A battery is a device that stores and provides electrical energy.
Q: Define closed circuit.
A: A closed circuit is a complete circuit through which current flows.
Q: Define open circuit.
A: An open circuit is an incomplete circuit where current cannot flow.
Q: What happens when a switch is turned off in a circuit?
A: When a switch is turned off, the circuit becomes open, and current stops
flowing.
Q: What is the unit of electric current?
A: The unit of electric current is ampere (A).
Q: What is the symbol for a closed switch?
A: The symbol for a closed switch is a straight line.
Q: What is the symbol for an open switch?
A: The symbol for an open switch is a break in the line.
Q: What does a series circuit mean?
A: In a series circuit, the components are connected one after another,
forming a single path.
Q: What happens to the brightness of bulbs in a series circuit when one
bulb goes off?
A: When one bulb goes off in a series circuit, all the bulbs in the circuit
also go off.
Q: What does a parallel circuit mean?
A: In a parallel circuit, the components are connected separately, forming
multiple paths.
Q: What happens to the brightness of bulbs in a parallel circuit when
one bulb goes off?
A: When one bulb goes off in a parallel circuit, the other bulbs remain lit.
Q: What is the symbol for a bulb in a circuit diagram?
A: The symbol for a bulb is a circle with a cross inside.
Q: What is a fuse?
A: A fuse is a safety device used to protect a circuit from excessive
current.
Q: What happens to a fuse when the current exceeds its capacity?
A: When the current exceeds the fuse's capacity, it melts and breaks the
circuit.
Q: What is the symbol for a fuse in a circuit diagram?
A: The symbol for a fuse is a rectangle with a diagonal line inside.
Q: What is the purpose of an electric switch?
A: An electric switch is used to control the flow of electricity in a
circuit.
Q: Define voltage.
A: Voltage is the measure of electrical potential energy in a circuit.
Q: What is the unit of voltage?
A: The unit of voltage is volt (V).
Q: What is the formula to calculate voltage?
A: Voltage = Current × Resistance (V = I × R).
Q: What is resistance?
A: Resistance is the opposition to the flow of electric current.
Q: What is the unit of resistance?
A: The unit of resistance is ohm (?).
Q: What is the formula to calculate resistance?
A: Resistance = Voltage / Current (R = V / I).
Q: What is an electric circuit diagram?
A: An electric circuit diagram is a graphical representation of an
electric
circuit using symbols.
Q: What is the role of a wire in an electric circuit?
A: A wire is used to connect the components of an electric circuit and
allows the flow of current.
Q: How can you increase the brightness of a bulb in a circuit?
A: By increasing the voltage or reducing the resistance in the circuit,
the
brightness of the bulb can be increased.
Q: How can you decrease the brightness of a bulb in a circuit?
A: By decreasing the voltage or increasing the resistance in the
circuit,
the brightness of the bulb can be decreased.
Q: Why do we use switches in electrical circuits?
A: Switches are used to control the flow of electricity, allowing us to
turn
devices on or off.
Q: How are electrons related to electricity?
A: Electrons are the subatomic particles that carry electric charges and
are
responsible for the flow of electricity.
Q: What is the difference between an AC and DC circuit?
A: In AC (Alternating Current) circuits, the current changes direction
periodically, while in DC (Direct Current) circuits, the current flows
in
only one
direction.
Q: What is the function of a resistor in a circuit?
A: A resistor is used to regulate or control the flow of current in a
circuit.
Q: What is a short circuit?
A: A short circuit occurs when a low resistance path is created in a
circuit, causing excessive current flow.
Q: What precautions should be taken while using electrical
appliances?
A: Avoid touching wet switches, use insulated gloves when dealing with
live
wires, and keep electrical appliances away from water to prevent
electric
shock.
Q: What is the purpose of grounding an electrical circuit?
A: Grounding an electrical circuit provides a conducting path for excess
electrical current and protects against electrical shock.
Q: How is electrical power calculated?
A: Electrical power can be calculated using the formula Power = Voltage
×
Current (P = V × I).
Q: What is the unit of electrical power?
A: The unit of electrical power is watt (W).
Q: Define electric shock.
A: Electric shock occurs when a person comes into contact with a live
electrical wire or device, leading to the flow of electric current
through
their body.
Q: What safety measures should be followed to avoid electric shock?
A: Avoid touching exposed wires, use socket covers, and never handle
electrical appliances with wet hands.
Q: Why are fuses or circuit breakers important in a circuit?
A: Fuses or circuit breakers protect the circuit from excessive current,
preventing damage to the circuit and appliances.
Q: What is the role of a circuit breaker in a circuit?
A: Circuit breakers automatically break the circuit when a fault or
excessive current is detected, thus protecting the circuit from damage.
Q: How can you reduce the resistance in a circuit?
A: By using thicker wire, reducing the length of the wire, or using a
material with lower resistivity, resistance in a circuit can be reduced.
Q: What is the purpose of using a voltmeter in a circuit?
A: A voltmeter is used to measure the voltage across different points in
an
electrical circuit.
Q: What is the purpose of using an ammeter in a circuit?
A: An ammeter is used to measure the electric current flowing through a
circuit.
Q: What are the advantages of using LED bulbs instead of
traditional
incandescent bulbs?
A: LED bulbs consume less energy, have a longer lifespan, and emit less
heat
compared to incandescent bulbs.
Chapter 13 Fun with Magnets
Question: What is a magnet?
Solution: A magnet is an object that attracts certain materials, like
iron and steel.
Question: What are the two poles of a magnet called?
Solution: The two poles of a magnet are called the North pole and the
South pole.
Question: What happens when the like poles of two magnets are
brought
close to each other?
Solution: When like poles of two magnets are brought close to each
other, they repel or push each other away.
Question: What happens when the opposite poles of two magnets are
brought close to each other?
Solution: When opposite poles of two magnets are brought close to each
other, they attract or pull each other towards.
Question: State two properties of a magnet.
Solution: Two properties of a magnet are attracting magnetic substances
and having two poles.
Question: Define the term 'magnetic field.'
Solution: The region around a magnet where its magnetic influence can be
felt is called a magnetic field.
Question: What is a temporary magnet?
Solution: A temporary magnet is a magnet that can be easily magnetized
or demagnetized.
Question: Give an example of a temporary magnet.
Solution: An example of a temporary magnet is a soft iron nail.
Question: What are permanent magnets?
Solution: Permanent magnets are magnets that retain their magnetism for
a long time.
Question: Mention a natural magnet.
Solution: Lodestone is a natural magnet.
Question: What is the importance of the Earth's magnetic field?
Solution: The Earth's magnetic field protects us from harmful cosmic
radiation and helps in navigation.
Question: What is the use of a magnetic compass?
Solution: A magnetic compass is used to find directions.
Question: What is magnetic separation?
Solution: Magnetic separation is a method used to separate magnetic and
non-magnetic substances.
Question: What is the use of a horseshoe magnet?
Solution: A horseshoe magnet is used to lift heavy iron objects like
nails and screws.
Question: Explain the process of magnetization.
Solution: Magnetization is the process of making an object into a magnet
by aligning its domains in a particular direction.
Question: What is the significance of the South pole of a magnet?
Solution: The South pole of a magnet always points towards the Earth's
geographic North Pole.
Question: How can you demagnetize a magnet?
Solution: Heating a magnet or hammering it can demagnetize it.
Question: What is electromagnetism?
Solution: The relationship between electricity and magnetism is called
electromagnetism.
Question: Define the term 'electromagnet.'
Solution: An electromagnet is a temporary magnet that is created when
electric current flows through a wire.
Question: What is the difference between a bar magnet and an
electromagnet?
Solution: A bar magnet is a permanent magnet, whereas an electromagnet
can be switched on and off.
Question: State two uses of electromagnets.
Solution: Electromagnets are used in electric bells and doorbells, as
well as in cranes to lift heavy objects.
Question: What is the principle behind how a Maglev train works?
Solution: The principle behind how a Maglev train works is
electromagnetic repulsion and attraction.
Question: Explain the working of an electric motor.
Solution: An electric motor works on the principle of electromagnetism
and converts electrical energy into mechanical energy.
Question: What is a solenoid?
Solution: A solenoid is a coil of wire that acts as an electromagnet
when current flows through it.
Question: What is the purpose of a commutator in a DC motor?
Solution: The commutator is used to change the direction of the current
in the coil of a DC motor.
Question: What is the function of a galvanometer?
Solution: A galvanometer is used to detect the presence and direction of
electric current.
Question: What is meant by magnetic declination?
Solution: Magnetic declination is the angle between the geographic and
magnetic North.
Question: What is the unit of magnetic field strength?
Solution: The unit of magnetic field strength is Tesla (T).
Question: What is a magnetic domain?
Solution: A magnetic domain is a region within a material where numerous
atomic magnets align in the same direction.
Question: What are the characteristics of the magnetic field around
a current-carrying wire?
Solution: The magnetic field around a current-carrying wire is circular
in shape and its strength decreases as you move away from the wire.
Question: How can you determine the direction of a magnetic field
around a current-carrying wire?
Solution: Apply the right-hand thumb rule: If you curl your right hand
around the wire with your thumb pointing in the direction of the
current, your fingers
will indicate the direction of the magnetic field.
Question: What does the term 'magnetic induction' refer to?
Solution: Magnetic induction refers to the process of inducing magnetism
in an object by bringing it close to a magnet.
Question: Define the term 'magnetic induction field.'
Solution: The magnetic field that is induced in a magnetic material when
it is brought close to a magnet is called the magnetic induction field.
Question: What is the difference between soft magnetic materials
and
hard magnetic materials?
Solution: Soft magnetic materials are easily magnetized and
demagnetized, while hard magnetic materials retain their magnetism.
Question: How does a doorbell work?
Solution: A doorbell works by using an electromagnet that attracts a
metal strip, creating a sound when the circuit is complete.
Question: What is the purpose of a magnetic shield?
Solution: A magnetic shield is used to protect sensitive electronic
devices from external magnetic fields.
Question: Can you list some common uses of magnets in our daily
life?
Solution: Yes, magnets are used in speakers, headphones, fridge magnets,
credit cards, and electricity generators, to name a few.
Question: What is the importance of magnets in medical imaging?
Solution: Magnets are used in technologies like magnetic resonance
imaging (MRI) to create detailed images of the human body for medical
diagnosis.
Question: How are magnetic levitation trains different from
traditional trains?
Solution: Magnetic levitation (Maglev) trains use powerful magnets to
levitate and propel the train, eliminating the need for wheels and
reducing friction.
Question: What is the function of a magnetic compass in navigation?
Solution: A magnetic compass is used by sailors, pilots, and hikers to
find directions and navigate accurately.
Question: How can you increase the strength of an electromagnet?
Solution: The strength of an electromagnet can be increased by
increasing the number of turns in the coil, increasing the current
passing through the coil, or
using an iron core.
Question: Explain how a fridge magnet works.
Solution: A fridge magnet works because it has a magnetic material,
usually iron, that can attract to the fridge, which is made of
ferromagnetic material.
Question: What is the role of a magnet in a generator?
Solution: In a generator, a magnet rotating within a coil of wire
induces a current, converting mechanical energy into electrical energy.
Question: How does the Earth's magnetic field impact migratory
birds?
Solution: Migratory birds like pigeons use the Earth's magnetic
field
for navigation during their long-distance journeys.
Question: Name a device that uses the principles of the
magnetic
field to measure electricity consumption.
Solution: An electricity meter, also known as an electric meter,
uses
magnetic field principles to measure the amount of electricity
consumed.
Question: How are magnets used in particle accelerators?
Solution: Magnets are used in particle accelerators to control and
steer
the high-speed particles along their desired path.
Question: What is the role of magnets in headphones and
speakers?
Solution: Magnets are used in headphones and speakers to convert
electrical signals into sound waves by vibrating a diaphragm.
Question: What is the function of a magnetic resonance
imaging (MRI)
machine?
Solution: An MRI machine uses powerful magnets to gather
detailed images
of the body's internal structures.
Question: How do magnets play a role in recycling?
Solution: Magnets are used to separate magnetic materials, such
as steel
cans, from non-magnetic materials during the recycling process.
Question: What is the impact of magnets on the data storage
industry?
Solution: Magnets are used in hard disk drives and tapes to
store and
retrieve data, making them essential for the data storage
industry.
Chapter 14 Water
Question: What percentage of the earth's surface is covered
with water?
Solution: Around 71% of the earth's surface is covered with
water.
Question: What are the three forms of water?
Solution: The three forms of water are liquid (water), solid
(ice), and gas (water vapor).
Question: Define the term 'water cycle.'
Solution: The continuous movement of water on, above, and below
the earth's surface is called the water cycle.
Question: How is rain formed?
Solution: Rain is formed when water droplets in the clouds
combine to form larger droplets that become heavy enough to fall
to the ground.
Question: What is the process of water changing from a
liquid
to a gas called?
Solution: The process of water changing from a liquid to a gas
is called evaporation.
Question: Name three sources of freshwater on earth.
Solution: Three sources of freshwater are rivers, lakes, and
underground water.
Question: What is groundwater?
Solution: Groundwater is the water present below the earth's
surface in the spaces between soil particles and rock layers.
Question: Explain the term 'water table.'
Solution: The upper level of groundwater found beneath the
earth's surface is called the water table.
Question: What is the process of water vapor turning back
into liquid called?
Solution: The process of water vapor turning back into liquid is
called condensation.
Question: State the importance of water for plants and
animals.
Solution: Water is essential for plants and animals for their
survival, growth, and reproduction.
Question: What is the role of water in the human body?
Solution: Water helps to regulate body temperature, transport
nutrients, remove waste, and maintain overall health.
Question: What is the largest source of saltwater on earth?
Solution: The largest source of saltwater on earth is the ocean.
Question: How do humans fulfill their need for freshwater?
Solution: Humans fulfill their need for freshwater by extracting
it from sources like rivers, lakes, and groundwater.
Question: What are the causes of water pollution?
Solution: Water pollution can be caused by industrial waste,
sewage, agricultural runoff, and improper disposal of chemicals.
Question: How can we conserve water at home?
Solution: We can conserve water at home by fixing leaks, using
water-efficient appliances, taking shorter showers, and turning
off taps when not in use.
Question: Name three methods of water conservation in
agriculture.
Solution: Irrigation management, drip irrigation, and rainwater
harvesting are three methods of water conservation in
agriculture.
Question: Define watershed.
Solution: A watershed is an area of land where all the water
drains into a common water body like a river, lake, or ocean.
Question: What is water scarcity?
Solution: Water scarcity refers to the shortage of freshwater
resources to meet the needs of a particular region or
population.
Question: How can excess water be harmful?
Solution: Excess water can lead to flooding, erosion, and the
destruction of crops, properties, and habitats.
Question: What is a water reservoir?
Solution: A water reservoir is an artificial lake created by
constructing a dam on a river to store water for various
purposes.
Question: Why is it important to conserve water resources?
Solution: It is important to conserve water resources to ensure
their availability for future generations and sustain the
environment.
Question: How is water treated before it reaches our homes?
Solution: Water is treated by filtration, disinfection, and
various chemical processes to remove impurities and make it safe
for consumption.
Question: Define the term 'water footprint.'
Solution: Water footprint refers to the total volume of
freshwater used to produce the goods and services consumed by an
individual, community, or nation.
Question: What is the significance of mangroves in water
conservation?
Solution: Mangroves act as natural filters, prevent coastal
erosion, provide habitat for marine organisms, and help maintain
the balance of aquatic ecosystems.
Question: Discuss the importance of rainwater harvesting.
Solution: Rainwater harvesting helps to conserve water, recharge
groundwater, reduce soil erosion, and provide an alternative
source of water for various
purposes.
Question: Explain the term 'desalination.'
Solution: Desalination is the process of removing salt and other
impurities from seawater to produce freshwater.
Question: How does pollution affect water bodies?
Solution: Pollution can contaminate water bodies, making them
unfit for drinking, endangering aquatic life, and disrupting
ecosystems.
Question: What are the effects of water scarcity on
agriculture?
Solution: Water scarcity can lead to reduced crop yields,
limited irrigation, and a decline in agricultural productivity.
Question: How can individuals contribute to water
conservation?
Solution: Individuals can conserve water by practicing
responsible water usage, avoiding wastage, and spreading
awareness about water conservation.
Question: Mention three diseases caused by unsafe drinking
water.
Solution: Cholera, typhoid, and dysentery are three diseases
caused by drinking unsafe water.
Question: What measures can be taken to prevent water
pollution?
Solution: Measures like proper waste disposal, treating
industrial effluents, and promoting eco-friendly practices can
prevent water pollution.
Question: How does temperature affect the state of water?
Solution: As temperature decreases, water changes from a liquid
to a solid (ice), and as temperature increases, it changes from
a liquid to a gas (water vapor).
Question: What is the importance of wetlands in water
conservation?
Solution: Wetlands help in water purification, flood control,
and provide a habitat for various plants and animals.
Question: How does deforestation impact water resources?
Solution: Deforestation can lead to soil erosion, reduced
groundwater recharge, and altered water flow patterns, affecting
the availability of water resources.
Question: What role does water play in agriculture?
Solution: Water is necessary for irrigation, crop growth, and
livestock farming in agriculture.
Question: Explain the concept of virtual water.
Solution: Virtual water refers to the amount of water embedded
within the production and trade of goods and services.
Question: What is the significance of the water cycle for
maintaining ecological balance?
Solution: The water cycle helps distribute water across
different regions, support plant growth, regulate climate, and
maintain ecological balance.
Question: How does water move from roots to leaves in a
plant?
Solution: Water moves from roots to leaves in a plant through
small tubes called xylem.
Question: Name two major rivers in India.
Solution: The Ganges and the Brahmaputra are two major rivers in
India.
Question: What are the effects of water pollution on
aquatic
life?
Solution: Water pollution can lead to the death of aquatic
organisms, loss of biodiversity, and disruptions in the food
chain.
Question: How can we prevent water wastage in daily
activities?
Solution: We can prevent water wastage by turning off taps while
brushing, using water-efficient appliances, and fixing leaky
pipes.
Question: Discuss the importance of water conservation
during droughts.
Solution: Water conservation becomes crucial during droughts to
ensure adequate water supply for drinking, irrigation, and
essential needs.
Question: What is the role of water in generating
hydroelectric power?
Solution: Water flowing through dams is used to turn turbines
and generate electricity in hydroelectric power plants.
Question: How does pollution impact underground water?
Solution: Pollution can seep into the ground and contaminate
underground water, making it unsuitable for drinking and
agricultural use.
Question: Why is it important to protect water bodies from
littering?
Solution: Littering can harm aquatic life, degrade water
quality, and disrupt the ecosystem of water bodies.
Question: Name three ways to reduce water pollution in
rivers.
Solution: Treating industrial waste, reducing fertilizer use in
agriculture, and proper waste management are ways to reduce
water pollution in rivers.
Question: What is the significance of water in the
formation
of clouds?
Solution: Water droplets evaporate, rise, and condense to form
clouds in the atmosphere.
Question: How does water regulate the earth's temperature?
Solution: Water absorbs and releases heat slower than land,
helping to regulate the earth's temperature and climate.
Question: What measures can be taken to conserve rainwater
on a small scale?
Solution: Installing rain barrels, using permeable pavements,
and creating rain gardens are measures to conserve rainwater on
a small scale.
Question: How does water facilitate the transportation of
nutrients in plants?
Solution: Water dissolves essential nutrients from the soil and
transports them through the roots, stems, and leaves of plants.
Chapter 15 Air Around Us
Q: What is air?
A: Air is a mixture of gases, mainly nitrogen (78%), oxygen
(21%), and traces of other gases like carbon dioxide and argon.
Q: What are the main components of air?
A: The main components of air are nitrogen, oxygen, carbon
dioxide, and argon.
Q: What is the importance of air?
A: Air is essential for all living organisms to breathe, helps
in the process of respiration, and maintains the Earth's
temperature.
Q: How is air necessary for burning?
A: Air contains oxygen, which supports combustion. Hence, air is
necessary for burning.
Q: Define the term 'atmosphere.'
A: The envelope of air surrounding the Earth is called the
atmosphere.
Q: What are the layers of the atmosphere?
A: The layers of the atmosphere, from closest to the Earth to
farthest, are troposphere, stratosphere, mesosphere,
thermosphere, and exosphere.
Q: What is the troposphere?
A: The troposphere is the lowest layer of the atmosphere and
extends up to around 10 km from the Earth's surface. Weather
changes occur in this layer.
Q: Why does the temperature decrease with increasing
altitude
in the troposphere?
A: The temperature decreases with increasing altitude because
the air becomes less dense and unable to retain heat.
Q: What is air pressure?
A: Air pressure is the force exerted by the weight of the air
above an area.
Q: What instrument is used to measure air pressure?
A: A barometer is used to measure air pressure.
Q: What is wind?
A: Wind is the movement of air from high-pressure areas to
low-pressure areas.
Q: Explain the term 'wind speed.'
A: Wind speed refers to how fast the air is moving horizontally
past a particular point.
Q: How is wind direction determined?
A: Wind direction is determined by the direction from which the
wind is blowing, usually measured using a wind vane.
Q: What causes wind?
A: The uneven heating of the Earth's surface causes differences
in air pressure, resulting in wind.
Q: Explain the term 'air pollution.'
A: Air pollution refers to the presence of harmful substances in
the air, causing damage to living organisms and the environment.
Q: What are some sources of air pollution?
A: Some sources of air pollution include vehicle emissions,
industrial factories, burning of fossil fuels, and agricultural
activities.
Q: What is acid rain?
A: Acid rain is rain that has a lower pH level than normal due
to the presence of sulfur and nitrogen pollutants in the air.
Q: How does air pollution affect human health?
A: Air pollution can cause respiratory problems, allergies, lung
diseases, and even lead to premature death in severe cases.
Q: What are some measures to reduce air pollution?
A: Measures to reduce air pollution include using cleaner energy
sources, regulating emissions, promoting public transportation,
and planting trees.
Q: Define the term 'oxygen.'
A: Oxygen is a colorless and odorless gas that is essential for
the survival of living organisms, as it is required for
respiration.
Q: Explain the process of respiration.
A: Respiration is the process of taking in oxygen and releasing
carbon dioxide to produce energy in living organisms.
Q: What is photosynthesis?
A: Photosynthesis is the process by which green plants use
sunlight, carbon dioxide, and water to produce oxygen and
glucose.
Q: How are plants important in maintaining the balance of
gases in the air?
A: During photosynthesis, plants release oxygen and absorb
carbon dioxide, helping to maintain the balance of gases in the
air.
Q: What is the greenhouse effect?
A: The greenhouse effect is the trapping of heat in the Earth's
atmosphere by certain gases, like carbon dioxide, resulting in
global warming.
Q: How can we reduce the greenhouse effect?
A: To reduce the greenhouse effect, we must reduce greenhouse
gas emissions, conserve energy, and promote sustainable
practices.
Q: What is the ozone layer?
A: The ozone layer is a layer of ozone gas in the Earth's
stratosphere that protects us from harmful ultraviolet (UV)
radiation.
Q: What causes the depletion of the ozone layer?
A: The depletion of the ozone layer is primarily caused by the
release of chlorofluorocarbons (CFCs) into the atmosphere from
human activities.
Q: Why is the ozone layer important?
A: The ozone layer is important as it shields the Earth from
harmful UV radiation, which can cause skin cancer, cataracts,
and harm ecosystems.
Q: What are CFCs, and why are they harmful?
A: CFCs (chlorofluorocarbons) are synthetic chemicals primarily
used in refrigeration and aerosol propellants. They are harmful
as they contribute to ozone
depletion.
Q: How can we protect the ozone layer?
A: We can protect the ozone layer by avoiding the use of
ozone-depleting substances, supporting regulations, and
promoting awareness.
Q: What is air resistance?
A: Air resistance is the force exerted by air on objects moving
through it, opposing their motion.
Q: Explain the process of convection.
A: Convection is the transfer of heat through the movement of
particles (in gases or liquids) due to differences in density
caused by temperature variations.
Q: What is the wind-chill factor?
A: The wind-chill factor is the temperature felt on the human
body due to the combined effects of wind and air temperature.
Q: How does wind affect weather?
A: Wind helps distribute heat and moisture around the Earth,
influencing weather patterns, such as temperature, humidity, and
precipitation.
Q: What are air masses?
A: Air masses are large bodies of air with similar temperature
and humidity characteristics across a region.
Q: How are air masses classified?
A: Air masses are classified based on their source region, which
determines the properties (temperature and humidity) of the air
mass.
Q: What is a cyclone?
A: A cyclone is a weather system characterized by inward
spiraling winds rotating around a low-pressure center.
Q: What is an anticyclone?
A: An anticyclone is a weather system characterized by outward
spiraling winds rotating around a high-pressure center.
Q: How does high humidity affect the human body?
A: High humidity can make the body feel hotter, as it affects
the body's ability to cool itself through sweating and
evaporation.
Q: How does air density change as altitude increases?
A: Air density decreases as altitude increases. At higher
altitudes, there are fewer air particles, resulting in lower
atmospheric pressure.
Q: Explain the term 'air quality.'
A: Air quality refers to the purity or cleanliness of the air,
determining its suitability for living organisms and
environmental health.
Q: What are primary pollutants?
A: Primary pollutants are directly emitted into the air from
sources, such as smokestacks or vehicle exhausts.
Q: What are secondary pollutants?
A: Secondary pollutants are formed in the atmosphere through
chemical reactions involving primary pollutants and other
substances.
Q: What is the role of wind in pollination?
A: Wind carries pollen grains from the male reproductive parts
of plants to the female reproductive parts, aiding in
pollination.
Q: What are the benefits of wind energy?
A: Wind energy is clean, renewable, and doesn't produce air
pollution or greenhouse gas emissions. It can be harnessed to
generate electricity.
Q: How does the presence of air bubbles affect the buoyancy
of an object?
A: The presence of air bubbles in an object decreases its
overall density, increasing its buoyancy in a fluid.
Q: What is the composition of air in terms of percentage?
A: Nitrogen makes up around 78% of air, while oxygen accounts
for approximately 21%. The remaining 1% consists of other gases
like carbon dioxide and
argon.
Q: Identify three methods by which we can reduce air
pollution in cities.
A: Three methods to reduce air pollution in cities include
promoting green transportation, encouraging the use of renewable
energy sources, and
implementing strict emission standards for industries.
Q: How does air pressure change with an increase in
altitude?
A: Air pressure decreases with an increase in altitude. As you
go higher, there is less air above, resulting in lower pressure.
Q: Why do we use oxygen masks in airplanes?
A: Oxygen masks are used in airplanes to provide passengers with
supplemental oxygen at high altitudes, where the air is thinner
and oxygen levels are lower.
Chapter 16 Garbage In Garbage Out
What is garbage?
Solution: Garbage refers to waste materials that are no longer
useful or needed by individuals or society.
Name two types of garbage.
Solution: Organic waste and inorganic waste.
Define organic waste.
Solution: Organic waste includes biodegradable materials like
food scraps, vegetable peels, leaves, etc.
Define inorganic waste.
Solution: Inorganic waste refers to non-biodegradable materials
such as plastic, glass, metal, etc.
What is the slogan associated with waste management?
Solution: "Reduce, Reuse, Recycle" is the slogan associated with
waste management.
Explain the 3Rs in waste management.
Solution: Reduce means using fewer resources and creating less
waste. Reuse involves using items multiple times. Recycle refers
to converting waste materials
into new products.
Explain the process of composting.
Solution: Composting is the natural decomposition of organic
waste into nutrient-rich compost. It involves collecting organic
waste, adding water and air, and
allowing it to decompose.
What is vermicomposting?
Solution: Vermicomposting is the process of using worms to break
down organic waste and produce nutrient-rich vermicompost.
Name any two sources of inorganic waste.
Solution: Plastic bottles and aluminum cans.
Explain the concept of recycling.
Solution: Recycling involves converting waste materials into new
products to conserve resources and reduce the amount of waste
sent to landfills.
Why should we avoid using plastic bags?
Solution: Plastic bags are non-biodegradable and take hundreds
of years to decompose. They contribute to environmental
pollution and harm wildlife.
How can you reduce garbage in your daily life?
Solution: By avoiding excessive packaging, using reusable bags,
containers, and water bottles, and recycling materials.
State one advantage of recycling.
Solution: Recycling conserves resources by reducing the need to
extract, refine, and process raw materials.
Define biodegradable waste.
Solution: Biodegradable waste refers to materials that can be
broken down naturally by bacteria or other living organisms.
Give an example of non-biodegradable waste.
Solution: Plastic bottles.
What is the purpose of a landfill?
Solution: Landfills are designated areas for the disposal of
waste materials, preventing contamination of surrounding soil
and water.
Mention one problem associated with landfills.
Solution: The release of harmful gases, such as methane, which
contribute to climate change.
What is e-waste?
Solution: Electronic waste or e-waste includes discarded
electronic devices like mobile phones, computers, and
televisions.
Why is it important to recycle e-waste?
Solution: Recycling e-waste prevents hazardous materials from
leaking into the environment and allows for the recovery of
valuable metals.
What is the role of a waste picker or ragpicker?
Solution: Waste pickers collect recyclable materials from
garbage and sell them to recycling centers, contributing to
waste management and recycling efforts.
How does the segregation of waste help in recycling?
Solution: Segregation helps separate different types of waste,
making recycling easier and more efficient.
What are the consequences of improper waste management?
Solution: Improper waste management leads to pollution,
health
hazards, and environmental degradation.
How can we reuse paper in everyday life?
Solution: By using both sides of the paper for writing or
printing, making crafts from old newspapers, or creating
homemade notepads.
Explain the concept of responsible consumption.
Solution: Responsible consumption involves making conscious
choices to reduce waste, conserve resources, and support
sustainable products.
What are the benefits of responsible consumption?
Solution: Benefits include reduced environmental impact,
cost
savings, and sustainability.
How can you contribute to waste management at school?
Solution: By promoting recycling, minimizing paper waste,
and
organizing waste segregation and collection systems.
Explain the concept of upcycling.
Solution: Upcycling involves converting waste materials into
new
and creative products with higher value.
How can you contribute to waste management in your
community?
Solution: Participating in cleanup drives, educating others
about waste management, and reducing personal waste
generation.
What is the role of biogas in waste management?
Solution: Biogas, produced from the anaerobic decomposition
of
organic waste, can be used as a renewable source of energy.
Discuss the importance of public awareness in waste
management.
Solution: Public awareness plays a key role in promoting
responsible waste management practices and fostering
sustainable
habits.
What measures can be taken to reduce food wastage?
Solution: Planning meals, storing food properly, and
donating
excess food to those in need.
Why is it necessary to treat sewage before releasing it
into
water bodies?
Solution: Sewage contains harmful bacteria and pollutants.
Treating it ensures the removal of these contaminants,
protecting water bodies and human health.
What are the harmful effects of burning garbage?
Solution: Burning garbage releases toxic fumes and
contributes
to air pollution.
Explain the concept of single-use plastics.
Solution: Single-use plastics are disposable items meant for
one-time use, such as straws, polystyrene cups, and plastic
cutlery.
Why should we avoid single-use plastics?
Solution: Single-use plastics create significant waste,
contribute to pollution, and harm ecosystems and wildlife.
Discuss the role of the government in waste management.
Solution: The government enforces waste management policies,
promotes recycling initiatives, and ensures proper waste
disposal.
How can you create awareness about waste management in
your
neighborhood?
Solution: Organizing awareness campaigns, distributing
informational pamphlets, and conducting workshops or
seminars.
How can you repurpose old clothes?
Solution: By transforming them into new garments, using them
as
cleaning rags, or donating them to those in need.
What are the benefits of composting?
Solution: Composting enriches the soil, reduces the need for
chemical fertilizers, and diverts organic waste from
landfills.
Discuss the importance of waste segregation at the
source.
Solution: Waste segregation at the source makes recycling
and
waste management more effective and efficient.
What is the significance of the 3Rs in waste
management?
Solution: The 3Rs, Reduce, Reuse, and Recycle, are essential
principles to minimize waste and promote sustainability.
How can you reduce water wastage in your daily life?
Solution: Turning off the tap while brushing teeth, fixing
leaky
faucets, and using water-efficient appliances.
Why is it important to follow the "no littering" rule?
Solution: Littering causes environmental pollution, disrupts
ecosystems, and harms wildlife.
Explain the importance of waste hierarchy.
Solution: Waste hierarchy prioritizes waste management
methods
according to their environmental impact, promoting
sustainable
practices.
What is the concept of "zero waste"?
Solution: Zero waste aims to minimize waste sent to
landfills by
adopting sustainable practices such as recycling,
composting,
and reusing.
How can you reduce plastic waste at home?
Solution: By using cloth bags instead of plastic ones,
opting
for glass or steel containers, and avoiding single-use
plastics.
Discuss the concept of extended producer responsibility
(EPR).
Solution: EPR makes producers responsible for the entire
lifecycle of their products, including their disposal and
recycling.
What measures can be taken to manage electronic waste
effectively?
