Physics Electronics PMDC Conceptual Practice
PMDC Verified Question 403 of 494
An AC voltage source with peak voltage \( V_m = 32.1\text{ V} \) is connected to a silicon diode (barrier potential \( 0.7\text{ V} \)) in a half-wave rectifier with a load resistance \( R_L = 10\text{ }\Omega \). What is the average DC load current?
A
\( 3.14\text{ A} \)
B
\( 0.50\text{ A} \)
C
\( 2.00\text{ A} \)
D
\( 1.00\text{ A} \)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: \( 1.00\text{ A} \)
Concept:

The peak load voltage in a practical half-wave rectifier accounts for the diode forward barrier voltage drop (\( V_B \)).

Formula:

$$I_{\text{dc}} = \frac{V_{m} - V_B}{\pi R_L}$$

Solution:

  • Calculate peak load voltage: \( V_{\text{peak, load}} = V_m - V_B = 32.1\text{ V} - 0.7\text{ V} = 31.4\text{ V} \).


  • Calculate peak current: \( I_m = \frac{31.4\text{ V}}{10\text{ }\Omega} = 3.14\text{ A} \).


  • Calculate average DC current:


  • $$I_{\text{dc}} = \frac{I_m}{\pi} = \frac{3.14\text{ A}}{3.1416} \approx 1.00\text{ A}$$


Why other options are incorrect:

  • Option A: \( 3.14\text{ A} \) is the peak load current (\( I_m \)), not the average DC current.
  • Option B: \( 0.50\text{ A} \) results from an extra division by 2.
  • Option C: \( 2.00\text{ A} \) is the DC current for a full-wave rectifier under the same conditions.

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.

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.