When a galvanometer is shunted by a resistance $S$, its current capacity increases $n$ times. If the same galvanometer is shunted by another resistance $S'$, its current capacity will increase to $n'$. The value of $n$ in terms of $n'$, $S$, and $S'$ is

$A$ moving coil galvanometer, when shunted with a $2\text{ }\Omega$ resistance, gives a full-scale deflection for a current of $500\text{ mA}$. When a resistance of $470\text{ }\Omega$ is connected in series, it gives a full-scale deflection for a potential of $10\text{ V}$ applied across it. The value of the resistance of the galvanometer coil is . . . . . . $\Omega$.

The phosphor bronze strip is used in a moving coil galvanometer because

$A$ galvanometer having a coil resistance of $100 \ \Omega$ gives a full-scale deflection when a current of $1 \ mA$ is passed through it. The value of the shunt resistance,which can convert this galvanometer into an ammeter giving a full-scale deflection for a current of $10 \ A$,is: ...... $\Omega$

Derive the expression for the shunt resistance required to increase the current-measuring capacity of a galvanometer by a factor of $n$.

$A$ galvanometer gives full scale deflection with $0.006 \ A$ current. By connecting it to a $4990 \ \Omega$ resistance,it can be converted into a voltmeter of range $0-30 \ V$. If connected to a $\frac{2n}{249} \ \Omega$ resistance,it becomes an ammeter of range $0-1.5 \ A$. The value of $n$ is: