Consider the following two statements $A$ and $B$ and identify the correct choice given in the answers.
$A$. Duddell's thermo-galvanometer is suitable to measure direct current only.
$B$. Thermopile can measure temperature differences of the order of $10^{-3} \, ^\circ C$.

The deflection in a moving coil galvanometer falls from $50$ divisions to $10$ divisions,when a shunt of $12 \Omega$ is connected with it. The resistance of the galvanometer coil is . . . . . . . (in $Omega$)

$A$ voltmeter of resistance $20000\,\Omega$ reads $5 \text{ V}$. To make it read $20 \text{ V}$,the extra resistance required is

When a resistance of $200 \Omega$ is connected in series with a galvanometer of resistance $G$,its range is $V$. To triple its range,a resistance of $2000 \Omega$ is connected in series. The value of $G$ is (in $Omega$)

The sensitivity of a galvanometer of resistance $171 \, \Omega$ becomes $1/20$ times when we use a shunt of $x \, \Omega$. Find $x$ ................. $\Omega$.

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