Question

The given figure shows an arrangement of single moving pulleys.

If the effort applied at the free end of the string is E; calculate the mechanical advantage of the system of pulleys.

• A. 2
• B. 4
• C. 6
• D. 8

Answer 1

The correct option is B

4

(a) Arrow sign $(\uparrow )$ in the figure shows the direction of the force exerted by four strings and magnitude is equal to the applied effort E.

In equilibrium, the load which can be lifted by the effort, L = 4T.
In equilibrium, L = 4T and E = T.
$\therefore$ Mechanical advantage $=\frac{4T}{T}=4$