Question

The values of maximum current and impedance in the given circuit are

• A. $1amp,300\Omega$
• B. $1amp,150\Omega$
• C. $3amp,100\Omega$
• D. $6amp,50\Omega$

Answer 1

The correct option is A $1amp,300\Omega$


Drawing phasors for each element separately,


Since the inductor and capacitor are connected in parellel, voltage across them are equal and in phase with each other.

$i_{0C}=\frac{300V}{X_C}=\frac{300}{60}=5A$
$i_{0L}=\frac{300V}{X_L}=\frac{300}{50}=6A$

Thus combining the phasors, we get


Hence, the current lags the voltage by phase angle $\frac{\pi }{2}$
i.e $i=i_0\sin (\omega t-\frac{\pi }{2})$
$i_0=1amp$
and Impedance $Z=\frac{V_0}{i_o}=\frac{300}{1}=300\Omega$