Full-wave rectifier output polarity: In a properly wired full-wave rectifier, the current through the load resistor flows ______ over time.

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:

• Full-wave rectification via either a center-tapped two-diode circuit or a bridge rectifier.
• Ideal diodes for conceptual clarity.
• Resistive load.

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:

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:

• Opposite directions: That describes AC directly across the load (no rectifier).
• ”From the reverse-biased diode”: Reverse-biased diodes do not conduct.
• ”To the external load”: Vague and does not address directionality.

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