Question

In the series $L C R$ circuit as shown in the figure, the voltmeter $V$ and ammeter $A$ readings are

• A. V=100 V, I=2 A
• B. V=100 V, I=5 A
• C. V=400 V, I=2 A
• D. V=300 V, I=2 A

Answer 1

Answer: (A)

As $V_{L}=V_{C} $
$\therefore X_{L}=X_{C}$
The circuit is resonance circuit.
Current, $I=\frac{100}{50}=2\, A$
As $V=\sqrt{V_{R}^{2}+\left(V_{L}-V_{C}\right)^{2}}$
$\therefore 100=\sqrt{V_{R}^{2}+0}=V_{R}$
or $V_{R}=100\, V$
Hence, the reading of the voltmeter $V$ is $100\, V$ and the reading of ammeter $A$ is $2 A$.