The ratios of the voltage sensitivities,resistances and areas of the coils of two moving coil galvanometers $A$ and $B$ are $4:3$,$3:4$ and $1:2$ respectively. If the number of turns of the coil of galvanometer $A$ is $200$,then the number of turns of the coil of galvanometer $B$ is (All other quantities remain same in both the cases)

If only $2 \%$ of the total current passes through an ammeter having a coil of resistance $R$,then the resistance of the shunt of the ammeter is:

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 $M_{1}$.

$A$ galvanometer having a coil resistance of $30\,\Omega$ shows full-scale deflection when a current of $2\,A$ passes through it. It can be converted into an ammeter to read currents up to $10\,A$ by:

What is the current sensitivity of a galvanometer? How can it be increased?

When a $12\,\Omega$ resistor is connected in parallel with a moving coil galvanometer,its deflection reduces from $50$ divisions to $10$ divisions. The resistance of the galvanometer is ............. $\Omega$.