Question

The shunt resistance needed for a galvanometer of $500\Omega$ to decreases its sensitivity by $100$ times is

• A. $505\Omega$
• B. $0.505\Omega$
• C. $50.5\Omega$
• D. $5.05\Omega$

Answer 1

The correct option is D $5.05\Omega$

Given, $G=500\Omega ;n=\frac{I}{I_g}=100$

Shunt resistance is,

$S=\frac{I_{g}G}{I-I_g}=\frac{G}{n-1}$

Where, $G-$ is Galvanometer resistance ; $n-$ is scaling factor

$S=\frac{G}{n-1}=\frac{500}{100-1}=\frac{500}{99}$

$S=5.05\Omega$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(D\right)$ is the correct answer.