Physics Electronics PMDC Conceptual Practice
PMDC Verified Question 73 of 494
If an AC source with peak voltage \( V_m = 100\text{ V} \) is rectified by an ideal half-wave rectifier, the root-mean-square (RMS) value of the output voltage is:
A
\( 70.7\text{ V} \)
B
\( 31.8\text{ V} \)
C
\( 63.6\text{ V} \)
D
\( 50.0\text{ V} \)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: \( 50.0\text{ V} \)
Concept:

The root-mean-square (RMS) value measures the effective heating value of the half-wave rectified waveform over a full \( 2\pi \) cycle.

Formula:

$$V_{\text{rms}} = \sqrt{\frac{1}{2\pi} \int_0^\pi (V_m \sin\theta)^2\,d\theta} = \frac{V_m}{2}$$

Solution:

  • For a half-wave rectifier:


  • $$V_{\text{rms}} = \frac{V_m}{2} = \frac{100\text{ V}}{2} = 50.0\text{ V}$$


Why other options are incorrect:

  • Option A: \( 70.7\text{ V} \) (\( V_m/\sqrt{2} \)) is the RMS output of a full-wave rectifier.


  • Option B: \( 31.8\text{ V} \) (\( V_m/\pi \)) is the average DC voltage of a half-wave rectifier.


  • Option C: \( 63.6\text{ V} \) (\( 2V_m/\pi \)) is the average DC voltage of a full-wave rectifier.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Electronics MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App