In an electric cell while in use, the change in energy is from:

1. electrical to mechanical
2. electrical to chemical
3. chemical to mechanical
4. chemical to electrical

Assertion (A): If momentum of a body increases by 50%, its kinetic energy will increase by 125%.

Reason (R): Kinetic energy is proportional to the square of velocity.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.

Name the form of energy which a wound-up watch spring possesses.

Name the type of energy (kinetic energy K or potential energy U) possessed in the following cases:

(a) A moving cricket ball

(b) A compressed spring

(c) A moving bus

(d) A stretched wire

(e) An arrow shot out of a bow.

(f) A piece of stone placed on the roof.