In terms of Physics, in which of the following cases, is the work being done?
1. A man pushing a wall but failing to move it
2. A coolie standing with a load of 12 kg on his head
3. A boy climbing up a staircase
4. A boy carrying a box on his head and sliding over a frictionless horizontal surface
Choose the correct option from the codes given below:

Answer: [D] Only 3

In case (iii) work is done, because displacement is produced in the direction of applied force. In cases (i), (ii) and (iv), no work is done as no displacement occurs in the direction of applied force.

This question is a part of GKToday's Integrated IAS General Studies Module