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

In a circuit,$5$ percent of the total current passes through a galvanometer. If the resistance of the galvanometer is $G$,then the value of the shunt is:

Two moving coil meters,$M_{1}$ and $M_{2}$ have the following particulars:
$R_{1}=10 \,\Omega, \quad N_{1}=30$
$A_{1}=3.6 \times 10^{-3} \,m^{2}, \quad B_{1}=0.25 \,T$
$R_{2}=14 \,\Omega, \quad N_{2}=42$
$A_{2}=1.8 \times 10^{-3} \,m^{2}, \quad B_{2}=0.50 \,T$
(The spring constants are identical for the two meters). Determine the ratio of
$(a)$ current sensitivity and
$(b)$ voltage sensitivity of $M_{2}$ and $M_{1}$.

The maximum current that can be measured by a galvanometer of resistance $40 \,\Omega$ is $10 \,mA$. It is converted into a voltmeter that can read up to $50 \,V$. The resistance to be connected in series with the galvanometer is ... (in $\Omega$)

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

$A$ 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?