Question

Show that an ideal inductor does not dissipate power in an ac circuit.

Answer 1

Power dissipation (P) = V_RMS I_RMS cos Φ

cos Φ = `R/Z`

For an ideal inductor,

R = 0

∴ cos Φ = 0

∴ P = V_RMS I_RMS cos Φ

= 0

Thus, an ideal inductor does not dissipate power in an ac circuit.