Question

A moving coil galvanometer has resistance $50\Omega$ and it indicates full deflection at $4\text{mA}$ current. A voltmeter is made using this galvanometer and a $5\text{k}\Omega$ resistance. The maximum voltage, that can be measured using this voltmeter will be close to

• A. $20\text{V}$
• B. $15\text{V}$
• C. $40\text{V}$
• D. $10\text{V}$

Answer 1

The correct option is A $20\text{V}$

Potential in the galvanometer is $V=i_g(G+R)=4\times {10}^{-3}(50+5000)\approx 20\text{V}$