Correct Answer - Option 3 : is given by mechanical advantage divided by velocity ratio
Explanation:
Efficiency:
It is the ratio of output to input. In a simple mechanism, it is also defined as the ratio of mechanical advantage to the velocity ratio.
\(\eta = \frac{{Output}}{{Input}} = \frac{{M.A}}{{V.R}}\)
In an ideal machine, the mechanical advantage is equal to the velocity ratio.
Mechanical Advantage (MA):
In a simple machine when the effort (P) balances a load (W), the ratio of the load to the effort is called Mechanical Advantage.
\(M.A = \frac{{Load}}{{Effort}} = \frac{W}{P}\)
Velocity Ratio:
It is the ratio between the distance moved by the effort to the distance moved by the load.
\(V.R = \frac{{Distance\;moved\;by\;the\;effort\;\left( {{d_P}} \right)}}{{Distance\;moved\;by\;the\;load\;\left( {{d_w}} \right)}}\)
