The range of an ammeter of resistance $G$ can be increased from $I$ to $nI$ by connecting

When a galvanometer is shunted with a $4\,\Omega$ resistance,the deflection is reduced to one-fifth. If the galvanometer is further shunted with a $2\,\Omega$ wire,the further reduction in the deflection will be (the main current remains same).

$A$ moving coil galvanometer has $100$ turns and each turn has an area of $2.0 \,cm^2$. The magnetic field produced by the magnet is $0.01 \,T$ and the deflection in the coil is $0.05$ radian when a current of $10 \,mA$ is passed through it. The torsional constant of the suspension wire is $x \times 10^{-5} \,N-m / rad$. The value of $x$ is . . . . . . .

$A$ moving coil sensitive galvanometer shows a large deflection. To control its speed of deflection (damping),which of the following is used?

$A$ moving coil galvanometer allows a full-scale current of $10^{-4} \ A$. $A$ series resistance of $2 \ M\Omega$ is required to convert the above galvanometer into a voltmeter of range $0-5 \ V$. Therefore,the value of shunt resistance required to convert the above galvanometer into an ammeter of range $0-10 \ mA$ is .... $\Omega$.

The resistance of an ammeter is $13\, \Omega$ and its scale is graduated for a current up to $100\, A$. After an additional shunt has been connected to this ammeter,it becomes possible to measure currents up to $750\, A$ by this meter. The value of the shunt resistance is: