Question

A resistor and an inductor are connected to an ac supply of $120V$ and $50Hz$. The current in the circuit is $3A$. If the power consumed in the circuit is $108W$, then the resistance in the circuit is

• A. $12\Omega$
• B. $40\Omega$
• C. $\sqrt{(52\times 28)}\Omega$
• D. $360\Omega$

Answer 1

The correct option is A $12\Omega$

$I_{rms}=currentincircuit=3A$
$P=108W=I_{rms}^{2}R=3^{2}R$
$R=108/9=12\Omega$