Ham Radio General Class Practice Test

What portion of the AC cycle is converted to DC by a half-wave rectifier?

1. 90 degrees

2. 180 degrees

3. 270 degrees

4. 360 degrees

The correct answer is: 180 degrees

A half-wave rectifier operates by allowing only one half of the AC cycle to pass through while blocking the other half. In standard AC waveforms, one full cycle consists of 360 degrees. In the case of a half-wave rectifier, it effectively utilizes only one half of that cycle, which corresponds to 180 degrees. During this portion, the rectifier allows the positive half of the waveform to be converted to a direct current (DC) output. The blocked portion, which is the negative half of the waveform, corresponds to the other 180 degrees of the 360-degree cycle. Thus, only the positive half, or 180 degrees of the entire AC waveform, is converted to DC. Understanding this mechanism is crucial for grasping how different types of rectifiers work and how they are applied in power supply circuits, particularly in systems requiring DC output from an AC source. This knowledge is foundational for those studying ham radio and various electronic applications.