In order to increase the sensitivity of a moving coil galvanometer,one should decrease

Two moving coil meters,$M_{1}$ and $M_{2}$ have the following particulars:
$R_{1}=10 \,\Omega, \quad N_{1}=30$
$A_{1}=3.6 \times 10^{-3} \,m^{2}, \quad B_{1}=0.25 \,T$
$R_{2}=14 \,\Omega, \quad N_{2}=42$
$A_{2}=1.8 \times 10^{-3} \,m^{2}, \quad B_{2}=0.50 \,T$
(The spring constants are identical for the two meters). Determine the ratio of
$(a)$ current sensitivity and
$(b)$ voltage sensitivity of $M_{2}$ and $M_{1}$.

Write the equation for the maximum torque acting on a current-carrying loop in a galvanometer.

The percentage error in the reading of the voltmeter in the figure shown here is nearly ............ $\%$

$A$ moving coil galvanometer of resistance $100 \,\Omega$ is used as an ammeter using a shunt resistance of $0.1 \,\Omega$. The maximum deflection current in the galvanometer is $100 \,\mu A$. Find the minimum current in the circuit so that the ammeter shows maximum deflection in $mA$.

By connecting a resistance of $980 \Omega$ in series with a galvanometer, it is converted into a voltmeter of a certain range. When the resistance of $470 \Omega$ is connected in series, the range is halved. The resistance of the galvanometer is (in $\Omega$)