Question

A voltmeter has a resistance of G ohms and range V volts. The value of resistance used in series to convert it into a voltmeter of range nV volts is

• A. nG
• B. $( n - 1 ) G$
• C. $\frac { G } { n }$
• D. $\frac { G } { ( n - 1 ) }$

Answer 1

Answer: (B)

$( n - 1 ) G$

Answer 2

Suppose resistance R is connected in series with voltmeter as shown.

By Ohm's law

$i _ { g } \cdot R = ( n - 1 ) V$

⇒ $R = ( n - 1 ) G$ (where $\left. i _ { g } = \frac { V } { G } \right)$