Which of the following are commonly used as rectifiers in electrical circuits?

• A. Anodes
• B. Cathodes
• C. Transistors
• D. Diodes

Answer: (D)

Rectification relies on a device that conducts current in one direction while blocking it in the opposite direction. Diodes fit this role because their PN junction allows forward conduction with a small drop and blocks reverse current. When connected to alternating current, a diode lets through only one polarity, producing pulsating DC after smoothing. For full-wave rectification, a bridge of four diodes uses both halves of the AC cycle to build a steady DC output. Anodes and cathodes are simply the two ends of a diode, not separate rectifying devices. Transistors can regulate or switch power, but they aren’t the basic rectifiers used to convert AC to DC. That makes diodes the common rectifying components.