$A$ voltmeter of resistance $R$ is to be used to measure the potential difference across a resistance $r$. In which case will the reading be nearest to the actual potential difference in the absence of the voltmeter?

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

$A$ moving coil galvanometer has a coil with $175$ turns and an area of $1 \, cm^2$. It uses a torsion band with a torsion constant of $10^{-6} \, N \cdot m/rad$. The coil is placed in a magnetic field $B$ parallel to its plane. The coil deflects by $10^{\circ}$ for a current of $1 \, mA$. The value of $B$ (in Tesla) is approximately:

In an ammeter, $0.2\%$ of the main current passes through the galvanometer. If the resistance of the galvanometer is $G$, the resistance of the ammeter will be

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

$A$ moving coil galvanometer of resistance $100 \Omega$ is used as an ammeter using a shunt resistance $0.1 \Omega$. The maximum deflection current in the galvanometer is $100 \mu A$. Find the total current in the circuit so that the ammeter shows maximum deflection. (in $mA$)