SAQ : Under what conditions work is not done although force is acting? 

Question

Under what conditions work is not done although force is acting? 

Answer

Work is not done when:

1. No Displacement: The force is applied, but there is no displacement of the object in the direction of the force.
2. Zero Force: The force applied is perpendicular to the direction of motion, resulting in zero work (e.g., pushing a book horizontally while it moves vertically).