Question

At resonance, electrostatic energy is ___________ the magnetic energy.

(a) Greater than

(b) Less than

(c) Equal to

(d) Depends on the circuit

The question was posed to me in final exam.

My question comes from Oscillation of Energy at Resonance in chapter Resonance in AC Circuits of Basic Electrical Engineering

Answer 1

Right choice is (c) Equal to

To explain I would say: At resonance, energy stored in the capacitor is equal to energy stored in the inductor because capacitive reactance and inductive reactance are equal at resonance.                                                                      The capacitor stores electrostatic energy and the inductor stores magnetic energy hence they are equal.