CBSE Class 4 EVS Revision Worksheet Set 07

Question 1(a). Define the following ( give one example) - Work
Answer: Work is said to be done when a force applied on an object moves the object over a certain distance in the direction of the applied force. Example: Pushing a heavy box across the floor.
In simple words: Work happens when an object moves because you push or pull it.
Exam Tip: Always remember that for scientific work to be done, two conditions must be met: application of force and movement of the object.

Question 1(b). Define the following ( give one example) - Energy
Answer: Energy is defined as the capacity or ability to do work. Example: A person eating food gets energy to run or play.
In simple words: Energy is the power or fuel required to do any task.

Exam Tip: Mention that without energy, no work can be done in the universe.

Question 1(c). Define the following ( give one example) - Force
Answer: Force is a push or a pull applied on an object that can change its state of motion, shape, or direction. Example: Kicking a football to make it move.
In simple words: Force is pushing or pulling something.

Exam Tip: State clearly that force can make stationary objects move or moving objects stop.

Question 2(i). Identify the type of force and write details -
Answer: Magnetic Force. Details: It is a non-contact force exerted by magnets. A horseshoe magnet pulls iron objects like pins and nails toward itself without touching them physically.
In simple words: Magnetic force is the pull of a magnet on iron objects without touching them.

Exam Tip: Classify it correctly as a non-contact force and mention magnets attracting iron.

Question 2(ii). Identify the type of force and write details -
Answer: Muscular Force. Details: It is the force exerted by the muscles of the body. A person cheering or lifting pom-poms uses the muscular force of their arms and body.
In simple words: Muscular force is the strength used by our body parts and muscles to move things.

Exam Tip: Keywords to include are body muscles, lifting, pushing, or pulling using limbs.

Question 2(iii). Identify the type of force and write details -
Answer: Frictional Force (Friction). Details: Friction is the opposing force that comes into play when two surfaces rub against each other. Sculptor chiseling stone overcomes resistance between tools.
In simple words: Friction is the force that slows down or stops things when they rub together.

Exam Tip: Always state that friction acts in the opposite direction of motion.

Question 3(i). Identify the type of energy and write details -
Answer: Solar Energy (Light and Heat Energy). Details: Energy obtained directly from the sun. It provides light to see and heat to warm up the earth, helping plants make food through photosynthesis.
In simple words: Solar energy is the light and warmth we get from the sun.

Exam Tip: Highlight that the sun is the primary and most abundant source of natural energy on Earth.

Question 3(ii). Identify the type of energy and write details -
Answer: Sound Energy. Details: Sound energy is produced by vibrating objects and travels in waves through a medium like air. Listening to music on a radio or music player uses sound energy.
In simple words: Sound energy is what we hear when things vibrate, like music or voices.
Exam Tip: Mention vibration as the core cause of sound energy.

Question 3(iii). Identify the type of energy and write details -
Answer: Electrical Energy. Details: Energy caused by the movement of electrons. It is used to run household appliances like glowing bulbs, fans, and televisions.
In simple words: Electrical energy is the power that runs lights, fans, and gadgets through wires.

Exam Tip: Give common examples of electrical appliances like bulbs and refrigerators.

Please refer to attached file for CBSE Class 4 EVS Revision Worksheet (4)