Question

In a galvanometer $5\%$ of the total current in the circuit passes through it. If the resistance of the galvanometer is $G$, the shunt resistance $5$ connected to the galvanometer is

• A. $19\, G$
• B. $\frac{G}{19}$
• C. $20\, G$
• D. $\frac{G}{20}$

Answer 1

Answer: (B)

Let the total passing be $I$.
Thus current passing through galvanometer
$I_{G}=0.05 I$
Also, current passing through shunt resistance
$I_{ s }=I-0.05 I=0.95 I$
Using $I_{5} S=I_{G} G$
$\therefore \frac{ S }{ G }=\frac{0.05}{0.95}=\frac{1}{10}$
$\Rightarrow S =\frac{ G }{19}$