(i) It is quite difficult to apply effort in the upward direction, if no fixed pulley P2 is used. The fixed pulley changes the direction of effort from upwards to downwards, making the application of the effort more convenient and easier.
(ii) As the movable pulley doubles the effort, ∴ Force, L = 2T
i.e., W = 2T
Mechanical advantage M.A. = 2T/T = 2
And V.R = Distance travelled by effort/Distance travelled by load = 2x/x = 2
The distance travelled by load is half the distance moved by effort = x/2.
(iii) Since W = 2T or 20 kgf = 2T Here, T = effort
∴ Effort applied = 20/2 = 10 kgf.