Question

In a single fixed pulley, the velocity ratio is alwaysthe mechanical advantage.

• A. equal to
• B. less than
• C. greater than or equal to

Answer 1

The correct option is C greater than or equal to

We know, that incase of single fixed pulley, distance by the effort is equal to distance moved by the load upward. If $d_E$ = d, $d_L$ = d

So, Velocity Ratio = $\frac{d_E}{d_L}$ = $\frac{d}{d}$ = 1

In ideal condition (frictional forces are zero or negligible), L = T and E = T

Mechanical advantage (MA) = $\frac{\text{Load}}{\text{Effort}}$ = $\frac{T}{T}$ = 1

However, if frictional forces (f) are not negligible,
L + F = T and E = T,
MA = $\frac{L}{E}=1-\frac{f}{E}$, which is less than 1.

Since VR = 1 and MA < 1, so in a single fixed pulley, the velocity ratio is always greater than equal to the mechanical advantage.