Physics Electronics PMDC Conceptual Practice
PMDC Verified Question 438 of 494
In a bridge rectifier circuit supplied by an AC peak secondary voltage \( V_m \), what is the Peak Inverse Voltage (\( \text{PIV} \)) across each non-conducting diode when the forward voltage drop (\( V_D \)) of the conducting diodes is taken into account?
A
\( \text{PIV} = V_m - V_D \)
B
\( \text{PIV} = 2 V_m - V_D \)
C
\( \text{PIV} = 2 V_m + 2 V_D \)
D
\( \text{PIV} = V_m + 2 V_D \)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: \( \text{PIV} = V_m - V_D \)
Concept:

Applying Kirchhoff's Voltage Law around the loop containing the transformer secondary, conducting diodes, and non-conducting diodes yields the practical Peak Inverse Voltage.

Formula:

$$\text{PIV} = V_m - V_D$$

Solution:

  • During conduction, one diode pair connects the load across the transformer secondary.


  • The reverse voltage across a non-conducting diode equals the peak supply voltage \( V_m \) minus the small forward voltage drop \( V_D \) of the conducting diode in series.


  • Therefore, \( \text{PIV} = V_m - V_D \approx V_m \).


Why other options are incorrect:

  • Option B: \( 2V_m - V_D \) applies to center-tapped full-wave rectifiers, where each diode must block both secondary halves.
  • Options C & D: Forward diode drops reduce the net reverse voltage seen by non-conducting diodes rather than increasing it.

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