# For Actual Lifting Machine

By Mohit Uniyal|Updated : June 29th, 2022

## For actual lifting machine, the mechanical advantage is

1. greater than the velocity ratio.
2. less than the velocity ratio
3. equal to the velocity ratio.
4. None of these

Ans: option B

## For actual lifting machine, the mechanical advantage is less than the velocity ratio.

Solution:

Mechanical advantage: In a lifting machine, the ratio of load lifted to the effort applied is known as mechanical advantage.

M.A. = Load lifted (W) / Effort applied (P)

The efficiency of a lifting machine: it is the ratio of mechanical advantage to the velocity ratio of the lifting machine.

Efficiency(η) = Mechanical advantage  (M.A.) / Velocity ratio (V.R.)

For an ideal lifting machine, the efficiency is 100% i.e. equal to one. Hence, for an ideal lifting machine;

Mechanical advantage  (M.A.) = Velocity ratio (M.A.)

For an actual lifting machine, the efficiency is less than one. Hence;

1>Efficiency(η)

1 > Mechanical advantage  (M.A.) / Velocity ratio (V.R.)

Mechanical advantage  (M.A.) < Velocity ratio (M.A.)

From the above expression it is clear that, for the actual lifting machine, the Mechanical advantage is less than the velocity ratio.