Question

Assertion : Work done in moving a body over a closed loop is zero for every force in nature.

Reason : Work done does not depend on nature of force.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (d) A and R are false

Explanation :

Work done in the motion of a body over a closed loop is zero only when the body is moving under the action of conservative forces (like gravitational or electrostatic forces). It is not zero when the forces are non-conservative e.g. frictional forces etc.