Question

If the reading of voltmeter $V_1$ , is $30V,$ What is the reading of voltmeter $V_2$ ?

• A. $20$
• B. $30$
• C. $40$
• D. $50$

Answer 1

Answer: (C)

$A.C$ . voltmeter reads $rms$ value of voltage.
RMS voltage applied $=\frac{V_0}{\sqrt{2}}=50V$
Reading of voltmeter $V_2$ is $x,$ then
$\sqrt{x^2+30^2}=50V$
$\Rightarrow x=40$ volt