Concept:In a pure inductor, current lags voltage by \(\phi = 90^\circ\). Over a complete cycle, the net energy transferred to the inductor is zero.
Formula / Reaction:$$P_{\text{avg}} = V_{\text{rms}} I_{\text{rms}} \cos\phi = V_{\text{rms}} I_{\text{rms}} \cos(90^\circ) = 0$$
Solution:- During quarter-cycles when current increases, energy is stored in the magnetic field: \(U = \frac{1}{2} L i^2\).
- During quarter-cycles when current decreases, this stored magnetic energy is fully returned to the source.
- The net energy consumed per cycle is zero.
Why other options are incorrect:- Opt_B: Real power dissipation for an in-phase pure resistive circuit.
- Opt_C: Represents reactive power, not real dissipated power.
- Opt_D: Peak power product, not cycle average.
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