Question

In the following circuit rms current through inductor is $0.8\, A$, the rms current through capacitor is $0.4\,A$ and rms current through resistor is $0.3 \,A$, the current delivered by a.c. source is

• A. 0.7 A
• B. 1.5 A
• C. 0.5 A
• D. Approximately 1 A

Answer 1

Answer: (C)

$I =\sqrt{I_{R}^{2}+\left(I_{L}-I_{c}\right)^{2}} $
$=\sqrt{(0.3)^{2}+(0.8-0.4)^{2}}$
$=\sqrt{(0.3)^{2}+(0.4)^{2}}=0.5 \,A$