21. Assertion : Newton’s third law of motion is applicable only when bodies are in motion. Reason : Newton’s third law applies to all types of forces, e.g. gravitational, electric or magnetic forces etc.

(a)       If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b)       If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c)        If assertion is true but reason is false.

(d)       If the assertion and reason both are false.

(e)       If assertion is false but reason is true.

Ans. e

(39)