1. Tardigrade
  2. Question
  3. Physics
  4. The voltmeter shown in figure reads 18 V across 50 ohm resistor. The resistance of voltmeter is nearly

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The voltmeter shown in figure reads 18 V across 50 ohm resistor. The resistance of voltmeter is nearlyPhysics Question Image

Solution:

Voltmeter reads 18 V
$\Rightarrow $ Potential difference across 24 $\Omega$ resistor
= 30 - 18 = 12 V
$\Rightarrow $ Current through battery = $\frac {12}{24}=0.5 A$
$\Rightarrow $ Let voltmeter resistance = x
Now current through 50 ohm is $\frac{18}{50}$
and current through voltmeter = $\frac{18}{x}$
$\frac{18}{50}+\frac{18}{x}=0.5 $
$\Rightarrow x = 128.5 \Omega$