# A pulley system consisting of four pulleys has efficiency as 90 percent . Calculate the mechanical advantage of the system

$noofpulley=velocityratio(V.R.)=4\phantom{\rule{0ex}{0ex}}efficiency\left(\eta \right)=90\%=\frac{90}{100}=\frac{9}{10}\phantom{\rule{0ex}{0ex}}\frac{M.A.}{V.R.}=\eta \phantom{\rule{0ex}{0ex}}\Rightarrow M.A.=\eta \times V.R.=\frac{9}{10}\times 4=3.6$

Mechanical advantage =3.6

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