Question

No work is done if the force acting on a body is:

विकल्प

• in the direction of displacement of body.

• at some acute angle in the direction of displacement of body.

• at right angles to the direction of displacement of body

• none of these

Answer 1

At right angles to the direction of displacement of body

Explanation:

Work is given by W = FS cos θ. At a right angle, θ = 90° and cos 90° = 0, so the work done is zero. A force in the direction of displacement, or at an acute angle to it, does non-zero work.