A galvanometer is used in laboratory for detecting the null point
Question:

A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of $6 \mathrm{~mA}$ it produces a deflection of $2^{\circ}$, its figure of merit is close to:

1. $3 \times 10^{-3} \mathrm{~A} / \mathrm{div}$

2. $333^{\circ} \mathrm{A} / \mathrm{div}$

3. $6 \times 10^{-3} \mathrm{~A} / \mathrm{div}$

4. $666^{\circ} \mathrm{A} / \mathrm{div}$

Correct Option: 1

Solution:

Figure of Merit $=C=\frac{i}{\theta}$

$=\mathrm{C}=\frac{6 \times 10^{-3}}{2}=3 \times 10^{-3} \mathrm{Am}^{2}$