WAEC - Physics (2008 - No. 16)

Which of the following equations for the efficiency of a machine is correct?

Efficiency = \(\frac{\text{Velocity Ratio}}{\text{Mechanical Advantage}}\) x 100%

Efficiency = \(\frac{input}{output}\) x 100%

Efficiency = \(\frac{\text{load distance}}{\text{effort distance}}\) x 100%

Efficiency = \(\frac{\text{Mechanical Advantage}}{\text{Velocity Ratio}}\) x 100%

EFFICIENCY is the ratio of useful work done by the machine to the total work put into the machine.