Difficulty: Easy
Correct Answer: in the same direction
Explanation:
Introduction / Context:Full-wave rectification is designed to convert both halves of an AC waveform into unidirectional current through the load, improving efficiency and reducing filter requirements compared with half-wave rectification. Understanding load current direction is fundamental to predicting ripple and sizing capacitors.
Given Data / Assumptions:
Concept / Approach:Each half-cycle of AC is routed so that the load always sees the same polarity. In a bridge, two diodes conduct on the positive half-cycle and the other two on the negative half-cycle, but current through the load keeps the same direction. In the center-tapped scheme, one diode conducts per half-cycle to maintain the same load polarity. Thus, the load current direction is constant over time (though its magnitude pulsates).
Step-by-Step Solution:
Track conduction paths for the positive half-cycle and note load current direction.Track conduction paths for the negative half-cycle; different diodes conduct, but load polarity is unchanged.Conclude that the load current flows in the same direction for both halves.Verification / Alternative check:Oscilloscope across the load shows a pulsating DC waveform that never reverses polarity. After adding a filter capacitor, ripple decreases, but polarity remains the same.
Why Other Options Are Wrong:
Common Pitfalls:Assuming current direction alternates because the input is AC; the rectifier topology specifically prevents this at the load.
Final Answer:in the same direction
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