In the circuit figure, the voltmeter reads 30 V . The resistance of the voltmeter is

Question

In the circuit figure, the voltmeter reads 30 V . The resistance of the voltmeter is <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-bgcpkm582xd5.png" /> (A) 1200 Ω  (B) 700 Ω  (C) 400 Ω  (D) 300 Ω

Tardigrade Admin · Accepted Answer

The potential difference across 300 Ω =60-30=30V Therefore the effective resistance of voltmeter resistance R and 400 Ω in parallel will be equal to 300 Ω , as 60 V is equally divided between two parts. So, 300 =(R × 400/R + 400) or 300R +120000=400R or R=1200 Ω

Q. In the circuit figure, the voltmeter reads $30 V$ . The resistance of the voltmeter is

$1200 Ω$

$700 Ω$

$400 Ω$

$300 Ω$

Q. In the circuit figure, the voltmeter reads 30V . The resistance of the voltmeter is

1200Ω

700Ω

400Ω

300Ω

The potential difference across 300Ω=60−30=30V Therefore the effective resistance of voltmeter resistance R and 400Ω in parallel will be equal to 300Ω , as 60 V is equally divided between two parts. So, 300 =R+400R×400​ or 300R+120000=400RorR=1200Ω

Q. In the circuit figure, the voltmeter reads $30 V$ . The resistance of the voltmeter is

$1200 Ω$

$700 Ω$

$400 Ω$

$300 Ω$