Assertion–Reason about rectifiers: Assertion (A): An ideal rectifier should have a unity harmonic factor. Reason (R): An ideal rectifier should have a unity displacement factor.

Introduction / Context:
Power quality in rectifiers is described by displacement factor (related to phase angle between fundamental voltage and current) and harmonic factor (ratio of harmonic RMS to fundamental RMS). This assertion–reason problem distinguishes these two metrics for an idealized rectifier current waveform.

Given Data / Assumptions:

• Ideal rectifier: zero device drop, instantaneous switching, purely resistive AC source.
• Current may be non-sinusoidal (contains harmonics), depending on topology and smoothing.
• Definitions: power factor = displacement factor * distortion factor (where distortion factor relates to harmonics).

Concept / Approach:
Unity displacement factor means the fundamental component of current is in phase with the supply voltage (cos φ = 1). Harmonic factor (HF) is not unity for a non-sinusoidal current; in fact, HF = Ih / If1, where Ih is RMS of all harmonics and If1 is RMS of the fundamental. For a perfectly sinusoidal current, harmonic factor would be zero, not one. Thus, stating that an ideal rectifier “should have unity harmonic factor” is incorrect, whereas stating it “should have unity displacement factor” can be valid for an idealized, phase-aligned fundamental.

Step-by-Step Solution:

Verification / Alternative check:

Why Other Options Are Wrong:

Common Pitfalls:

Final Answer: