Question

When a high resistance $R$ is connected in series with a voltmeter of resistance $G$, the range of the voltmeter increases $5$ times. Then $G:R$ will be :

• A. $4:1$
• B. $1:2$
• C. $8:1$
• D. $1:4$

Answer 1

The correct option is D $1:4$

Given range is increased by $5$ times $=\frac{V_1}{V_2}=\frac{1}{5}=\frac{R_1}{R_2}=\frac{G}{R+G}$

$R+G=5G⟹R=4G=\frac{G}{R}=\frac{1}{4}$