The deflection in a moving coil galvanometer is

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

“By increasing current sensitivity,voltage sensitivity is also increased”. This statement is true or false.

$A$ galvanometer of $50 \, \Omega$ resistance has $25$ divisions. $A$ current of $4 \times 10^{-4} \, A$ gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of $25 \, V$, it should be connected with a resistance of

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 $M_{1}$.

In a ballistic galvanometer,the frame on which the coil is wound is non-metallic to