$A$ galvanometer having coil resistance $10 \ \Omega$ shows a full scale deflection for a current of $3 \ mA$. For it to measure a current of $8 \ A$,the value of the shunt should be:

When a galvanometer is shunted by a resistance $S$,its current capacity increases $n$ times. If the same galvanometer is shunted by another resistance $S^{\prime}$,its current capacity increases to $n^{\prime}$. The value of $n^{\prime}$ in terms of $n, S$ and $S^{\prime}$ is

Explain the use of a galvanometer as a voltmeter.

$A$ galvanometer of resistance $G$ can be converted into a voltmeter of range $V$ by connecting a resistance $R$ in series with it. The series resistance required to change its range to $\frac{V}{3}$ is

To find the resistance of a galvanometer by the half-deflection method,the following circuit is used with resistances $R_1 = 9970\,\Omega$,$R_2 = 30\,\Omega$,and $R_3 = 0\,\Omega$. The deflection in the galvanometer is $d$. With $R_3 = 107\,\Omega$,the deflection changes to $\frac{d}{2}$. The galvanometer resistance is approximately ............... $\Omega$.

To verify Ohm's law,a student is provided with a test resistor $R_T$,a high resistance $R_1$,a small resistance $R_2$,two identical galvanometers $G_1$ and $G_2$,and a variable voltage source $V$. The correct circuit to carry out the experiment is