*Question G7A03:
Which type of rectifier circuit uses two diodes and a center-tapped transformer?*  

*Correct Answer is  A: Full-wave*  

### AI Response: (may contain errors)  

The correct answer to the question is **A: Full-wave**. Here's the explanation:

1. **Why the correct answer is correct:**
   - A full-wave rectifier circuit that uses a center-tapped transformer employs two diodes. Each diode conducts during one half of the AC cycle, allowing both halves of the input waveform to be utilized. This results in a smoother DC output compared to a half-wave rectifier, which only uses one half of the waveform.

2. **Why the other choices are incorrect:**
   - **B: Full-wave bridge**: This type of rectifier uses four diodes arranged in a bridge configuration and does not require a center-tapped transformer. It rectifies both halves of the AC waveform but does so without the need for a center tap.
   - **C: Half-wave**: A half-wave rectifier uses only one diode and only rectifies one half of the AC waveform. It does not utilize a center-tapped transformer and results in a more pulsating DC output.
   - **D: Synchronous**: A synchronous rectifier typically uses MOSFETs or other active devices to improve efficiency and reduce voltage drop. It is not specifically related to the use of diodes and a center-tapped transformer.

3. **Useful formulas or rules of thumb:**
   - For a full-wave rectifier using a center-tapped transformer, the average output voltage ($V_{avg}$) can be approximated as:
   $$
   V_{avg} = \frac{2 \times V_{peak}}{\pi}
   $$
   where $V_{peak}$ is the peak voltage from the transformer secondary winding.

This explanation should help clarify the concepts related to rectifier circuits for your Extra Class exam preparation.