Question

A moving coil galvanometer has a resistance of $900\Omega$. In order to send only $10$% of the main current through this galvanometer, the resistance of the required shunt is:

• A. $0.9\Omega$
• B. $100\Omega$
• C. $405\Omega$
• D. $90\Omega$

Answer 1

Answer: (B)

$100\Omega$

Since the $10$% current is required to pass through galvanometer, and $90$% through the shunt, the ratio of the resistances must be $\frac{R_{shunt}}{R_{Gal}}=\frac{1}{9}$

Thus $R_{shunt}=100\Omega$