A galvanometer needs $25 \mathrm{mV}$ for a full scale deflection of $50$ divisions. Find its voltage sensitivity. What must be its resistance if its current sensitivity is $1 \mathrm{div}/20 \mathrm{\mu A}$?

Compare the current sensitivity and voltage sensitivity of the following moving coil galvanometers: $M_1$ and $M_2$:

$N_1=30, A_1=1.5\times {10}^{-3} {\mathrm{m}}^2$,

$B_1=0.25 T, {\mathrm{R}}_1=20 \mathrm{\Omega }$,

$N_2=35, A_2=2.0\times {10}^{-3} {\mathrm{m}}^2$,

$B_2=0.25 \mathrm{T}, {\mathrm{R}}_2=30 \mathrm{\Omega }$.

You are given that the springs in the two meters have the same torsional constants.