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

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:

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