The current sensitivity of moving coil galvanometer is increased by 25 % . This increase is achieved only…

The current sensitivity is given as

$S_i=\frac{NBA}{C}$.

The voltage sensitivity is

$S_v=\left(\frac{NAB}{CR}\right)$, where $R$ is the galvanometer resistance.

Since the resistance is constant,
$\Delta S_i=\left(\Delta S_v\right)$

Hence, the percentage change in voltage sensitivity is,

$\left(\Delta S_v\right)=+25\%$.