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

$A$ galvanometer is used in a laboratory for detecting the null point in electrical experiments. If, on passing a current of $6 \ mA$, it produces a deflection of $2^{\circ}$, its figure of merit is close to (each division is $1^{\circ}$):

$A$ moving coil galvanometer has $100$ equal divisions. Its current sensitivity is $10$ divisions per milliampere and voltage sensitivity is $2$ divisions per millivolt. In order that each division reads $1 \ V$,the resistance in Ohm's needed to be connected in series with the coil will be

In a circuit,$5$ percent of the total current passes through a galvanometer. If the resistance of the galvanometer is $G$,then the value of the shunt is:

$A$ galvanometer of resistance $50 \ \Omega$ is connected to a battery of $8 \ V$ along with a resistance of $3950 \ \Omega$ in series. $A$ full-scale deflection of $30$ divisions is obtained in the galvanometer. In order to reduce this deflection to $15$ divisions,the resistance in series should be . . . . . . $\Omega$.

Two moving coil galvanometers,$X$ and $Y$,have coils with resistances $10 \Omega$ and $14 \Omega$,cross-sectional areas $4.8 \times 10^{-3} \ m^2$ and $2.4 \times 10^{-3} \ m^2$,and number of turns $30$ and $45$ respectively. They are placed in magnetic fields of $0.25 \ T$ and $0.50 \ T$ respectively. Find the ratio of their current sensitivities and the ratio of their voltage sensitivities.