Question

What is the mechanical advantage of a single movable pulley?

• A. 1
• B. 2
• C. 0.5
• D. 1.5

Answer 1

The correct option is B

2

A pulley which can change its axis of rotation is called a single movable pulley. It can move up or down with a load.

In the given figure, a single movable pulley is shown. When effort (E) is applied at the free end, a tension (T) is produced in the string. This sets tension on either side of the string in the upward direction. In equilibrium, total tension in the string in the upward direction should be balanced by the load (W) in the downward direction. In equilibrium, W = 2T and E = T
$\therefore$ Mechanical advantage $=\frac{Load}{Effort}=\frac{W}{E}=\frac{2T}{T}=2$