Question

A voltmeter of resistance $ 1000\,\Omega $ gives full scale deflection when a current of $ 100\,mA $ flows through it. The shunt resistance required across it to enable it to be used as an ammeter reading $ 1\,A $ at full scale deflection is

• A. $ 10000\,\Omega $
• B. $ 9000\,\Omega $
• C. $ 222\,\Omega $
• D. $ 111\,\Omega $

Answer 1

Answer: (D)

By using $ \frac{i}{i_{g}}=1+\frac{1000}{S} $
$ \frac{i}{100\times 10^{-3}}=1+\frac{1000}{S} $
$ \Rightarrow S=\frac{1000}{9} $
$=111\,\Omega $