Two identical galvanometers are converted into a voltmeter and a millivoltmeter. As compared to the series resistance of the voltmeter,the series resistance of the millivoltmeter will be

If only $\frac{1}{51}$ of the main current is to be passed through a galvanometer,then the shunt required is $R_1$. If only $\frac{1}{11}$ of the main voltage is to be developed across the galvanometer,then the resistance required is $R_2$. Find the ratio $\frac{R_2}{R_1}$.

When an additional resistance $1980 \ \Omega$ is connected in series with a voltmeter,each scale division has $100$ times larger value. The resistance of the voltmeter is (in $\Omega$)

The range of a voltmeter of resistance $G \ \Omega$ is $V$ volt. The resistance required to be connected in series with it in order to convert it into a voltmeter of range $nV$ volt, will be

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 $M_{1}$.

$A$ galvanometer,whose resistance is $50\, \Omega$,has $25$ divisions. When a current of $4 \times 10^{-4}\, A$ passes through it,its needle deflects by one division. To use this galvanometer as a voltmeter of range $2.5\, V$,it should be connected to a resistance of ....... $\Omega$.