## Efficiency:

It is the ratio of output to the input of a machine and is generally expressed as a percentage. Mathematically,

efficiency (η) = (Output/Input) x 100

## Mechanical Advantage:

The mechanical advantage is the ratio of weight lifted (W) to the effort applied (P) and is always expressed in pure numbers. Mathematically,

Mechnaical Advantage (M.A) = W/P

## Velocity ratio:

The velocity ratio is the ratio of the distance moved by the effort (y) to the distance moved by the load (x) and is always expressed in pure number. Mathematically,

velocity ratio (V.R) = y/x