OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीConsider the following statements regarding the work done by a constant force \( \mathbf{F} \) on an object: (A) Work done is zero if the displacement of the object is zero, even if the applied force is large. (B) Work done is zero if the force acts perpendicularly to the direction of displacement. (C) The frictional force can never do negative work on an object. (D) Work done is positive if the angle between force and displacement is an acute angle (\( 0^\circ \le \theta < 90^\circ \)). Choose the correct answer from the options given below:
Correct answer · Option 1
(A), (B) and (D) only
Explanation
Work \( W = F d \cos\theta \). Statements (A), (B), and (D) are correct. Statement (C) is incorrect because friction opposes relative displacement (\( \theta = 180^\circ \)), doing negative work.
