Rectifier topologies and diode counts: Match each rectifier with the number of diodes required. List I (Rectifier) List II (Number of diodes) A. Full-wave bridge rectifier 1. 1 B. Half-wave rectifier 2. 2 C. Full-wave rectifier with centre-tapped transformer 3. 4
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AA-1, B-2, C-3
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BA-4, B-1, C-2
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CA-2, B-1, C-3
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DA-3, B-1, C-2
Answer
Correct Answer: A-3, B-1, C-2
Explanation
Introduction / Context:Different rectifier circuits achieve DC conversion with different device counts and transformer requirements. Counting diodes correctly is a frequent exam task and a practical design consideration.
Given Data / Assumptions:
- Bridge rectifier uses four diodes in a full-wave configuration.
- Half-wave rectifier uses one diode.
- Full-wave rectifier with centre-tapped secondary uses two diodes.
Concept / Approach:
Associate each topology with its conduction paths per half-cycle and tally the required diodes.
Step-by-Step Solution:
Bridge: two diodes conduct on each half-cycle; total required = 4 ⇒ A-3.Half-wave: only one diode rectifies a single half-cycle ⇒ B-1.Centre-tap full-wave: one diode per half of the secondary ⇒ C-2.Verification / Alternative check:
Standard power-supply schematics confirm the diode counts and current paths, matching the mapping.
Why Other Options Are Wrong:
- Any mapping that assigns fewer than 4 diodes to a bridge rectifier is incorrect.
- Using more than one diode for half-wave is unnecessary and not standard.
Common Pitfalls:
Confusing “diodes conducting at a time” with “diodes required in the circuit.” In a bridge, two conduct at once, but the circuit still needs four.
Final Answer:
A-3, B-1, C-2