An ideal ammeter and an ideal voltmeter have resistances of . . . . . . $\Omega$ and . . . . . . $\Omega$ respectively.

An ammeter of resistance $20 \Omega$ gives full scale deflection when $1 \text{ mA}$ current flows through it. What is the maximum current that can be measured by connecting $4$ resistors each of $16 \Omega$ in parallel with the meter (in $\text{ mA}$)?

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.

Only $4 \%$ of the total current in the circuit passes through a galvanometer. If the resistance of the galvanometer is $G$,then the shunt resistance connected to the galvanometer is:

$A$ galvanometer of resistance $50 \ \Omega$ is connected to a battery of $8 \ V$ along with a resistance of $3950 \ \Omega$ in series. $A$ full-scale deflection of $30$ divisions is obtained in the galvanometer. In order to reduce this deflection to $15$ divisions,the resistance in series should be . . . . . . $\Omega$.

When a shunt of $4\,\Omega$ is connected to a galvanometer,the deflection reduces to $1/5$ of its initial value. If an additional shunt of $2\,\Omega$ is connected in parallel,what will be the new deflection?