An ideal series LC circuit has Xʟ = 30 Ω and Xᴄ = 50 Ω at the operating frequency. If v = 40 sinωt V is applied, determine the current.
Options

Question

An ideal series LC circuit has Xʟ = 30 Ω and Xᴄ = 50 Ω at the operating frequency. If v = 40 sinωt V is applied, determine the current.

G1 Physics · Accepted Answer

The net impedance is j[Xʟ − Xᴄ] = −j20 Ω. Its magnitude is 20 Ω, so current amplitude is 40/20 = 2 A. Since the circuit is net capacitive, current leads voltage by 90°.