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

The sensitivity of a galvanometer of resistance $406\, \Omega$ is decreased by $30$ times. The shunt used is .................. $\Omega$.

$A$ moving coil galvanometer has $50$ turns and each turn has an area $2 \times 10^{-4} \ m^2$. The magnetic field produced by the magnet inside the galvanometer is $0.02 \ T$. The torsional constant of the suspension wire is $10^{-4} \ N \ m \ rad^{-1}$. When a current flows through the galvanometer,a full-scale deflection occurs if the coil rotates by $0.2 \ rad$. The resistance of the coil of the galvanometer is $50 \ \Omega$. This galvanometer is to be converted into an ammeter capable of measuring current in the range $0-1.0 \ A$. For this purpose,a shunt resistance is to be added in parallel to the galvanometer. The value of this shunt resistance,in ohms,is:

When a resistance of $100 \Omega$ is connected in series with a galvanometer of resistance $G$,its range is $V$. To double its range,a resistance of $1000 \Omega$ is connected in series. The value of $G$ is: (in $\Omega$)

If only $2 \%$ of the total current passes through an ammeter having a coil of resistance $R$,then the resistance of the shunt of the ammeter is:

Explain: "Increasing the current sensitivity may not necessarily increase the voltage sensitivity".