$A$ galvanometer of resistance $50 \Omega$ is connected to a battery of $3 \text{ V}$ along with a resistance of $2950 \Omega$ in series,showing a full-scale deflection of $30$ divisions. The additional series resistance required to reduce the deflection to $20$ divisions is: (in $\Omega$)

When a $12\,\Omega$ resistor is connected in parallel with a moving coil galvanometer,its deflection reduces from $50$ divisions to $10$ divisions. The resistance of the galvanometer is ............. $\Omega$.

In the circuit (Figure) the current is to be measured. What is the value of the current if the ammeter shown:
$(a)$ is a galvanometer with a resistance $R_{G}=60.00 \; \Omega$;
$(b)$ is a galvanometer described in $(a)$ but converted to an ammeter by a shunt resistance $r_{s}=0.02 \; \Omega$;
$(c)$ is an ideal ammeter with zero resistance?

$A$ microammeter has a resistance of $100\,\Omega$ and a full-scale range of $50\,\mu A$. It can be used as a voltmeter or a higher-range ammeter provided a resistance is added to it. Pick the correct range and resistance combination$(s)$.

$A$ student uses the resistance of a known resistor $(1 \,\Omega)$ to calibrate a voltmeter and an ammeter using the circuits shown below. The student measures the ratio of the voltage to current to be $1 \times 10^3 \,\Omega$ in circuit $(a)$ and $0.999 \,\Omega$ in circuit $(b)$. From these measurements,the resistance (in $\Omega$) of the voltmeter and ammeter are found to be close to

To convert a galvanometer into an ammeter,a shunt of $0.01\,\Omega$ is used. The resistance of the galvanometer coil is $50\,\Omega$ and its maximum deflection current is $20\,mA$. The range of the ammeter is: