Question

A coil of inductance $L$ has an inductive reactance of $X_L$ in an AC circuit in which the effective current is $I$. The coil is made from superconducting material and has no resistance. The rate at which power is dissipated in the coil is

• A. $0$
• B. $L{X}_L$
• C. $I^2{X}_L{L}_{L}L$
• D. $I{X}_L^2$

Answer 1

Answer: (A)

It is a pure inductive circuit.
$\theta =90^{\circ }$
$P=V_{\text{eff }}\cdot I_{\text{eff }}\cos \theta$
$=V_{\text{eff }}\cdot I_{\text{eff }}\cos 90^{\circ }=0.$