Advanced Qualification · A-004 Power supplies · A-004-001-010
In a high voltage power supply, why should a resistor and capacitor be wired in parallel with the power-supply rectifier diodes?
- ATo decrease the output voltage
- BTo ensure that the current through each diode is about the same
- CTo equalize voltage drops and guard against transient voltage spikes
- DTo smooth the output waveform
Correct answer: C — To equalize voltage drops and guard against transient voltage spikes. From the official ISED question bank, verified word for word.
Why
When rectifier diodes are stacked to handle high voltage, slight manufacturing differences can cause one diode to take more voltage than the others, risking failure. The full explanation — and one for every question — is in Pro.
Practise this section
Power supplies is section A-004 of the Advanced exam: Power supplies: rectifiers, filtering, regulation, switching supplies and their failure modes.
Drill A-004 — free, no account