Question

A galvanometer has resistance $36\Omega$. If a shunt of $4\Omega$ is added with this, then fraction of current that passes through galvanometer is :-

• A. $\frac{1}{4}$
• B. $\frac{1}{9}$
• C. $\frac{1}{10}$
• D. $\frac{1}{40}$

Answer 1

Answer: (C)

$\frac{1}{10}$
Current flowing through $R_G$ in figure 1 =Current flowing through $R_G$ in figure 2 = $I_1=\left(\frac{4}{40}\right)\times I=\frac{I}{10}$

Fraction$\Rightarrow \frac{\frac{I}{10}}{I}=\frac{1}{10}$