In an AC circuit, the fundamental component of the current lags the corresponding voltage by 20°. What is the phase relationship of the third-harmonic current component with respect to its corresponding voltage component?

Introduction / Context:
In AC circuits with harmonics, phase shift between current and voltage is frequency dependent because the impedance of reactive components changes with frequency. The question explores the behavior of the third harmonic in relation to the fundamental when the fundamental lags by 20°.

Given Data / Assumptions:

• Fundamental current lags voltage by 20°.
• Third harmonic frequency = 3 times fundamental frequency.
• Circuit contains reactive elements (inductive or capacitive).

Concept / Approach:
In an inductive circuit, phase angle = arctan(XL / R) increases with frequency because XL = ωL grows with frequency. Thus, higher harmonics lag more than the fundamental. In a capacitive circuit, phase lead increases with frequency, but since problem states lag, inductive behavior is implied.

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