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

Which one of the following modifications may increase the sensitivity of a moving coil galvanometer?
$1^{st}$ Way: By using a spring of smaller torsion constant.
$2^{nd}$ Way: By using a smaller coil.
$3^{rd}$ Way: By using a stronger magnet.
$4^{th}$ Way: By using a coil having fewer number of turns.

$A$ galvanometer of $100\,\Omega$ resistance gives full-scale deflection when $10\,mA$ of current is passed. To convert it into a $10\,A$ range ammeter,the resistance of the shunt required will be ............... $\Omega$.

$A$ galvanometer of resistance $50 \Omega$ is converted to an ammeter. After shunting,the effective resistance of the ammeter is $2.5 \Omega$. The value of the shunt is

$A$ galvanometer of resistance $G$ has a voltage range $V_g$. The resistance required to convert it to read voltage up to $V$ is

$A$ galvanometer of resistance $30 \Omega$ is connected to a battery of emf $2 \text{ V}$ with $1970 \Omega$ resistance in series. $A$ full-scale deflection of $20$ divisions is obtained in the galvanometer. To reduce the deflection to $10$ divisions,the total resistance in series required is: (in $\Omega$)