The relationship between mechanical advantage (M.A.) and velocity ratio (V.R.) for a practical machine is:

1. M.A.= V.R.
2. M.A.> V.R.
3. M.A.< V.R.
4. None of these

A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. The ratio of the two effort is:

1. 1:2
2. 2:1
3. 1:1
4. none of these

How many strands are supporting the load in case of block and tackle system of 4 pulleys when effort is in downward direction?

1. 5
2. 4
3. 3
4. 6