$A$ voltmeter of resistance $20000\,\Omega$ reads $5 \text{ V}$. To make it read $20 \text{ V}$,the extra resistance required is

Two galvanometers $G_{1}$ and $G_{2}$ require $2 \ mA$ and $3 \ mA$ respectively to produce the same deflection. Then:

What is a shunt? Explain its function in a circuit,obtain the formula for the shunt,and explain its uses.

If the number of turns in the coil of a galvanometer is decreased,then the resistance of the galvanometer:

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)

$A$ galvanometer has a deflection of $25$ divisions for a current of $0.1 \ A$ flowing through it. Then the current sensitivity of the galvanometer is (in $div/A$)