Explanation

(c) Let G be resistance of galvanometer and $i_{g}$ the current which on passing through the galvanometer produces full scale deflection. If $i$ is the maximum current, and since, G and S are in parallel.
$i_{g} \times G = \left( i - i_{g} \right) \times S$
$\Longrightarrow \frac{i_{g}}{i} = \frac{S}{S + G}$
Given, G=36$\Omega$, S=4$\Omega$
$\therefore\ \frac{i_{g}}{i} = \frac{4}{36 + 4} = \frac{4}{40}$
$\Longrightarrow i_{g} = \frac{i}{10}$
$\therefore\ \ 100 \times \frac{i_{g}}{i} = \frac{1}{10} \times 100\ $
$\Longrightarrow \ \frac{i_{e}}{i}\% = 10\%$