$A$ galvanometer has a resistance of $20\,\Omega$ and reads full-scale when $0.2\,V$ is applied across it. To convert it into a $10\,A$ ammeter,the galvanometer coil should have a

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 $M_{1}$.

$20\%$ of the main current passes through the galvanometer. If the resistance of the galvanometer is $G$,then the resistance of the shunt will be

The resistance of an ammeter is $13\, \Omega$ and its scale is graduated for a current up to $100\, A$. After an additional shunt has been connected to this ammeter,it becomes possible to measure currents up to $750\, A$ by this meter. The value of the shunt resistance is:

$A$ galvanometer of resistance $10 \Omega$ changes its range from $1 \text{ mA}$ to $101 \text{ mA}$ when a resistive wire is connected in parallel. If the resistivity of the material of the wire and its area of cross-section are $1 \times 10^{-6} \Omega \text{ m}$ and $1 \text{ mm}^2$ respectively,then the length of the wire is (in $cm$)

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