Question

An inductor coil is connected to a capacitor and an $AC$ source of rms voltage $8V$ in series. The rms current in the circuit is $16A$ and is in phase with emf. If this inductor coil is connected to $6VDC$ battery, the magnitude of steady current is

• A. 8 A
• B. 10 A
• C. 12 A
• D. 16 A

Answer 1

Answer: (C)

Given,
$rms$ voltage of $AC$ source $V_{rms}=8V$ and the $rms$
current in the circuit, $I_{rms}=16A$
According to the question,

$\therefore$ Impedance of the circuit,
$Z=\frac{V_{rmS}}{I_{rms}}=\frac{8}{16}$
$Z=0.5\Omega$
When the inductor coil is connected to a $6VDC$
battery then $V_{rms}^{{}^{\prime }}=6V=V_{DC}$
$\therefore$ Magnitude of steady current,
$I^{{}^{\prime }}=\frac{V_{rms}^{{}^{\prime }}}{Z}=\frac{6}{0.5}=12A$