The pulley system is used in a machine:

1. for gain in energy
2. as a force multiplier
3. as a force multiplier and for a gain in energy 
4. none of these

A single fixed pulley is used because it:

1. has a mechanical advantage greater than 1
2. has a velocity ratio less than 1
3. gives 100% efficiency
4. helps to apply the effort in a convenient direction.

The mechanical advantage of an ideal single movable pulley is:

1. 1
2. 2
3. less than 2
4. less than 1.

Which of the following statements is incorrect?

1. The velocity ratio of a single fixed pulley is always 1.
2. The velocity ratio of a single movable pulley is always 2.
3. The velocity ratio of a combination of n movable pulleys with a fixed pulley is always 2ⁿ.
4. The velocity ratio of a block and tackle system is always equal to the number of strands of the tackle supporting load.