Question

In a single movable pulley system, a load of 225 kgf is lifted by an effort of 75 kgf. Velocity ratio of the single movable pulley is 4. Find the percentage efficiency of the system.

• A. 0%
• B. 50%
• C. 75%
• D. 100%

Answer 1

The correct option is C

75%

Given, load (L) = 225 kgf
Effort (E) = 75 kgf and velocity ratio (VR ) = 4

We know that,
Mechanical Advantage (MA) $=\frac{\text{Load (L)}}{\text{Effort (E)}}=\frac{225}{75}=3$

Also, Efficiency % = $\frac{\text{MA}}{\text{VR}}\times 100$

$=\frac{3}{4}\times 100=75$