*Question G7A05:
What portion of the AC cycle is converted to DC by a half-wave rectifier?*  

*Correct Answer is  B: 180 degrees*  

### AI Response: (may contain errors)  

A half-wave rectifier is a circuit that converts alternating current (AC) into direct current (DC) by allowing only one half of the AC cycle to pass through. Here's how it works:

1. **AC Cycle Basics**: An AC cycle is a sinusoidal waveform that completes one full cycle in 360 degrees. This cycle consists of two halves:
   - The positive half-cycle (0 to 180 degrees)
   - The negative half-cycle (180 to 360 degrees)

2. **Half-Wave Rectification**: A half-wave rectifier only allows one half of the AC cycle to pass through, typically the positive half-cycle. This means it converts 180 degrees of the AC cycle into DC.

3. **Correct Answer**: 
   - **180 degrees**: This is the portion of the AC cycle that is converted to DC by a half-wave rectifier, as it only allows one half (either positive or negative) of the cycle to pass.

4. **Why Other Choices Are Incorrect**:
   - **90 degrees**: This would imply that only a quarter of the cycle is converted, which is not the case for a half-wave rectifier.
   - **270 degrees**: This would suggest that more than half of the cycle is converted, which is not possible with a half-wave rectifier.
   - **360 degrees**: This would mean the entire cycle is converted, which is characteristic of a full-wave rectifier, not a half-wave rectifier.

In summary, a half-wave rectifier converts 180 degrees of the AC cycle to DC, corresponding to one half of the waveform.