$A$ small cylindrical soft iron piece is kept in a galvanometer so that

In a moving coil galvanometer,the deflection of the coil $\theta$ is related to the electrical current $i$ by the relation

The deflection in a moving coil galvanometer is reduced to half when it is shunted with a $X \ \Omega$ coil. The relation between $X$ and the resistance of the galvanometer $G$ is:

$A$ microammeter has a resistance of $100\,\Omega$ and a full-scale range of $50\,\mu A$. It can be used as a voltmeter or a higher-range ammeter provided a resistance is added to it. Pick the correct range and resistance combination$(s)$.

Certain galvanometers have a fixed core made of non-magnetic metallic material. The function of this metallic material is

Only $4 \%$ of the total current in the circuit passes through a galvanometer. If the resistance of the galvanometer is $G$,then the shunt resistance connected to the galvanometer is: