Question

$20\%$ of the main current passes through the galvanometer. If the resistance of the galvanometer is $G$, then the resistance of the shunt will be -

• A. $\frac{G}{50}$
• B. $\frac{G}{4}$
• C. $50G$
• D. $9G$

Answer 1

The correct option is B $\frac{G}{4}$


$i=i_1+i_2$

$i_1=20\%$ of $i=0.2i$

$\therefore i_2=0.8i$

Now,

$i_{1}G=i_{2}S$

$\Rightarrow 0.2i\times G=0.8i\times S$

$\Rightarrow S=\frac{G}{4}$

Hence, option $\left(B\right)$ is the correct answer.