A voltmeter can read up to (V) volt. When the series resista... | Physics | SolveeIt | Solveeit

Today, August 18

Question

A voltmeter can read up to $V$ volt. When the series resistance used in the voltmeter is doubled, range of voltmeter is

A

$V$

B

$2 V$

C

less than $2 V$

D

more than $2 V$

Answer

less than $2 V$

Explanation

Solution

Reading of voltmeter
$V = l_g (G + R)$ ... (i)
If resistance $R$ is increased to $2R$ , the reading of voltmeter,
$V' = l_g(G + 2R) = 2V - I_g G$ (Using (i))