*Question G7A07:
What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load?*  

*Correct Answer is  A: A series of DC pulses at twice the frequency of the AC input*  

### AI Response: (may contain errors)  

In a full-wave rectifier, the entire AC waveform is used to produce DC output. Here's how it works:

1. **Correct Answer: A series of DC pulses at twice the frequency of the AC input**
   - A full-wave rectifier inverts the negative half-cycles of the AC input, effectively doubling the number of pulses per cycle. 
   - If the AC input frequency is $f$, the output frequency of the rectified waveform is $2f$.
   - This results in a series of DC pulses at twice the frequency of the AC input.

2. **Why the other choices are incorrect:**
   - **B: A series of DC pulses at the same frequency as the AC input**
     - This would be true for a half-wave rectifier, which only uses one half of the AC cycle, resulting in pulses at the same frequency as the input.
   - **C: A sine wave at half the frequency of the AC input**
     - A rectifier does not produce a sine wave; it converts AC to DC. Additionally, the frequency is doubled, not halved.
   - **D: A steady DC voltage**
     - The output of an unfiltered full-wave rectifier is not steady; it consists of pulsating DC. A steady DC voltage would require additional filtering to smooth out the pulses.

In summary, a full-wave rectifier outputs a waveform with DC pulses at twice the frequency of the AC input, which is why choice A is correct.