Question

In the series $L C R$ circuit (see figure), the voltmeter and ammeter readings are:

• A. $V=100\, V , I=2 \,A$
• B. $V=100\, V , I=5 \,A$
• C. $V=1000 \,V , I=2 \,A$
• D. $V=300 \,V , I=1 \,A$

Answer 1

Answer: (A)

Here $V_{ L }=V_{ C }$. They are in opposite phase. Hence, they will cancel each other. Now the resultant potential difference is equal to the applied potential difference $=100 \,V$
$ Z=R \,\,\left(\therefore X_{ L }=X_{ C }\right) $
$\therefore I_{ rms }=\frac{V_{ rss }}{Z}$
$=\frac{V_{ rms }}{R}=\frac{100}{50}=2\, A$