Question

In the $\text{AC}$ network shown in the figure, the $\text{RMS}$ current flowing through the inductor and capacitor are $0.6\text{A}$ and $0.8\text{A}$ respectively. Then, the current coming out of the source is

• A. $1\text{A}$
• B. $1.4\text{A}$
• C. $0.2\text{A}$
• D. None of the above

Answer 1

The correct option is C $0.2\text{A}$

For parallel $LC$ combination, from phasor

Current, $\overrightarrow{i}=\overrightarrow{i_C}+\overrightarrow{i_L}$

And voltage across both will be same.

In capacitor, current leads with respect to voltage by $\frac{\pi }{2}$ while in inductor, current lags with respect to voltage by $\frac{\pi }{2}$.


From phasor

$i_{rms}=(i_C{)}_{rms}-(i_L{)}_{rms}$

$=0.8-0.6$

$\therefore i_{rms}=0.2\text{A}$

Hence, option $\left(\text{C}\right)$ is correct.