A coolie A takes 1 minute to lift a load to the roof of a bus whereas coolie B take 2 minutes to lift the same load to the roof of the same bus. The work done by B is:

1. equal to work done by A
2. greater than work done by A
3. less than work done by A
4. none of the above.

One horse power is equal to :

1. 1000 W
2. 500 W
3. 764 W
4. 746 W

The energy of electron is 2.5 eV. When expressed in Joule, it is

1. 1.6 x 10^-19 J
2. 4.0 x 10^-19 J
3. 3.2 x 10^-19 J
4. 0

A block of mass 20 kg is pulled up a slope as shown in the figure given below with a constant speed by applying a force of 200 N parallel to the slope from the initial position A to the final position B. Work done in moving the block from A to B is:

1. 600 J
2. 500 J
3. 60 J
4. 200 J