$A$ galvanometer of resistance '$G$' is shunted by a resistance of '$S$' ohm. To keep the main current in the circuit unchanged,the resistance to be put in series with the galvanometer is:

The current sensitivity of a moving coil galvanometer can be increased by

$A$ voltmeter of $250 mV$ range having a resistance of $10 \Omega$ is converted into an ammeter of $250 mA$ range. The value of the necessary shunt is (nearly): (in $\Omega$)

For designing a voltmeter of range $50\,V$ and an ammeter of range $10\,mA$ using a galvanometer which has a coil of resistance $54\,\Omega$ showing a full scale deflection for $1\,mA$ as in figure.
$(A)$ for voltmeter $R \approx 50\,k\Omega$
$(B)$ for ammeter $r \approx 0.2\,\Omega$
$(C)$ for ammeter $r \approx 6\,\Omega$
$(D)$ for voltmeter $R \approx 5\,k \Omega$
$(E)$ for voltmeter $R \approx 500 \Omega$
Choose the correct answer from the options given below

$A$ multirange current meter can be constructed by using a galvanometer circuit as shown in the figure. We want a current meter that can measure $10 \text{ mA}$,$100 \text{ mA}$,and $1 \text{ A}$ using a galvanometer of resistance $10 \text{ } \Omega$ that produces maximum deflection for a current of $1 \text{ mA}$. Find the values of $S_1, S_2$,and $S_3$ that have to be used.

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?