Question

The given figure shows a block and tackle system of pulleys used to lift a load.
What is the mechanical advantage of the system?

• A. 3
• B. 5
• C. 4
• D. 2

Answer 1

The correct option is C 4

There are four strands of tackle supporting the load.

The arrow sign $(\uparrow )$ shows the direction of the tension in each strand. If the load attached to the system is L, effort applied at the free strand is E, and the number of pulleys (n) = 4, then in equilibrium:
L = 4T and E = T
$\therefore$ Mechanical advantage $=\frac{\text{L}}{\text{E}}=\frac{\text{4T}}{\text{T}}=4$