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

Two moving coil galvanometers $A$ and $B$ having identical springs are placed in magnetic fields of $0.25 \ T$ and $0.5 \ T$ respectively. If the number of turns in $A$ and $B$ are respectively $36$ and $48$,and the areas of the coils $A$ and $B$ are $2.4 \times 10^{-3} \ m^2$ and $4.8 \times 10^{-3} \ m^2$ respectively,then the ratio of the current sensitivities of the galvanometers $A$ and $B$ is

$A$ shunt of resistance $1\,\Omega$ is connected across a galvanometer of $120\,\Omega$ resistance. $A$ total current of $5.5\,A$ is passed through the combination,which gives full-scale deflection in the galvanometer. The current that would give full-scale deflection in the absence of the shunt is nearly ............... $A$.

$A$ moving coil galvanometer,having a resistance $G$,produces full scale deflection when a current $I_g$ flows through it. This galvanometer can be converted into $(i)$ an ammeter of range $0$ to $I_0$ $(I_0 > I_g)$ by connecting a shunt resistance $R_A$ to it and $(ii)$ into a voltmeter of range $0$ to $V$ $(V = GI_0)$ by connecting a series resistance $R_V$ to it. Then,

If only $2\%$ of the main current is to be passed through a galvanometer of resistance $G$,then the resistance of the shunt will be

The pole pieces of the magnet used in a pivoted coil galvanometer are