Question
Establish a relationship between efficiency, $M.A.$, and $V.R.$

Answer

Let a machine overcome a load $L$ by applying an effort $E$. In time $t$, the displacement of effort is $d _{ E }$, and displacement of load is $d _{ L }$. Then
Work input $=$ Effort $\times$ Displacement of effort $=E \times d_E$
Work output $=$ Load $\times$ Diaplacement of load $=L \times d_L$
Efficiency =
$\frac{\text { Work output }}{\text { Work input }}=\frac{ L \times d _{ L }}{ E \times d _{ E }}=\frac{ L / E }{ d _{ E } / d _{ L }}$
$L / E = M.A$. and $d_E / d_L= V.R.$
Efficiency $=\frac{\text { M.A. }}{\text { V.R. }}$
$M.A. = V.R. \times $ Efficiency.

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