Question

A parallel combination of pure inductor and capacitor is connected across a source of alternating e.m.f. 'e'. The currents flowing through an inductor and capacitor are i_L and i_C respectively. In this parallel resonant circuit, the condition for currents i, i_L and i_C is (i = net r.m.s. current in the circuit)

Options

• i/i_L = i_C

• i ≠ 0, i_L = i_C = 0

• i/0, i_L = i_C ≠ 0

• i/0, i_L ≠ i_C

Answer 1

i/0, i_L = i_C ≠ 0

Explanation:

In parallel resonant circuit, the capacitive and inductive reactance are equal, hence currents are equal but 180° out of phase with each other. The net current is zero. ∴ i = 0, i₂ = i_c ≠ 0