CBSE Class 4 EVS Revision Worksheet Set 08

Ques 1) Name and write in detail about the various sources of energy.
Answer:

In simple words: Different sources like the Sun, wind, water, and fuels give us energy to do work and run machines.
Exam Tip: Memorize at least four primary sources of energy along with their practical applications.

Ques 2) Circle the odd one out and give a reason for your answer.

(a) T.V, Petrol, Diesel, Coal
Answer: (a) T.V
Reason: Petrol, diesel, and coal are fuels that provide energy, whereas a T.V is an appliance that consumes electrical energy to produce picture and sound.
In simple words: T.V is an electronic device, while the rest are fuel sources of energy.

Exam Tip: Always identify the common category among three items to easily spot the odd one out.

(b) Wind, Water, Gravity, Sun
Answer: (b) Gravity
Reason: Wind, water, and the Sun are natural sources of energy, whereas gravity is a force of attraction exerted by the Earth.
In simple words: Gravity is a force, while the others are energy sources.

Exam Tip: Distinguish clearly between physical forces (like gravity or friction) and natural energy sources.

(c) Alarm clock, Music system, Sun, Doorbell
Answer: (c) Sun
Reason: Alarm clock, music system, and doorbell produce sound energy, whereas the Sun is a natural source of heat and light energy.
In simple words: The Sun gives us light and heat, while the others are sound-making devices.

Exam Tip: Look closely at the type of energy or function each object produces.

(d) Screwdriver, Wrench, Hammer, Fan
Answer: (d) Fan
Reason: Screwdriver, wrench, and hammer are hand tools used for repairing or manual work, whereas a fan is an electrical appliance used for cooling.
In simple words: A fan runs on electricity, while the others are manual tools.

Exam Tip: Classify items based on whether they are manual tools or electrical machines.

Ques 3) Fill in the blanks-

i) We get heat energy from the Sun (or fire / fuels).
Answer: The Sun
In simple words: The Sun is our main natural heater.

Exam Tip: Remember that the Sun is the ultimate source of heat and light on Earth.

ii) TV's work on electrical energy.
Answer: electrical
In simple words: Televisions need electricity to turn on.

Exam Tip: Most home appliances run on electrical energy.

iii) A stone falling down is because of gravity.
Answer: gravity
In simple words: Earth pulls everything downwards.

Exam Tip: Gravity is the invisible pull exerted by the Earth on all objects.

iv) The force applied to put a nail in the wall is called muscular force.
Answer: muscular force
In simple words: We use muscle power to hammer a nail.

Exam Tip: Forces applied using body muscles are termed muscular forces.

v) Force can change the shape, speed, or direction of a resting object.
Answer: state of motion or position (or shape/speed/direction)
In simple words: Force can move things that are stopped or change how they move.

vi) The force applied by the earth is called gravitational force (or gravity).
Answer: gravitational force
In simple words: Earth's pull is called gravity.
Exam Tip: Gravitational force always pulls objects toward the center of the Earth.

vii) Energy is the ability or capacity of a body to do work.
Answer: Energy, ability
In simple words: Energy is our capacity to perform any task.

Exam Tip: This is the standard scientific definition of energy. Memorize it word for word.

viii) Wind energy can blow the sails of a boat.
Answer: sails
In simple words: Moving wind pushes boat sails forward.

Exam Tip: Wind energy has been used for centuries to navigate sailing ships.

Ques 4) Draw and label -

(a) Any two types of energy
Answer:
Steps / Description:
1. Draw a glowing Sun with rays to represent Solar/Light Energy.
2. Draw a battery or a lightning bolt to represent Electrical Energy.
In simple words: We can illustrate energy types like solar and electrical energy using simple icons like the Sun and a lightning bolt.

Exam Tip: Keep diagrams neat, simple, and clearly labeled with proper arrows.

(b) Any two types of force
Answer:
Steps / Description:
1. Draw a hand lifting a box to represent Muscular Force.
2. Draw a magnet attracting iron nails to represent Magnetic Force.
In simple words: Muscular force uses body strength, and magnetic force pulls iron objects.

Exam Tip: Label push/pull or magnetic poles clearly in force diagrams.

(c) Any two sources of energy
Answer:
Steps / Description:
1. Draw a wind turbine with blades to represent Wind energy.
2. Draw a wood log or coal lump to represent Fuel energy.
In simple words: Windmills capture wind and coal stores fuel energy.

Exam Tip: Practice drawing basic scientific objects like windmills and sun symbols accurately.