SSC JE Electrical Engineering 2017 Set 3 Paper

A multimeter uses different multiplies to increase the voltage range.Resistance is connected in series with moving coil to increase the voltage range of multimeter
${\mathit{V}}_{\mathit{m}}={\mathit{I}}_{\mathit{m}}{\mathit{R}}_{\mathit{m}}$
after connecting multiplier resistance (${\mathit{R}}_{\mathit{S}}$ )
${\mathit{V}}_1={\mathit{I}}_{\mathit{m}}\left({\mathit{R}}_{\mathit{m}}+{\mathit{R}}_{\mathit{s}}\right)$
$\frac{\mathit{V}}{{\mathit{V}}_{\mathit{m}}}=\left(1+\frac{{\mathit{R}}_{\mathit{s}}}{{\mathit{R}}_{\mathit{m}}}\right)$
$\frac{\mathit{V}}{{\mathit{V}}_{\mathit{m}}}=\mathit{m}$ (multiplying factor)