*Question E7B01:
For what portion of the signal cycle does each active element in a push-pull, Class AB amplifier conduct?*  

*Correct Answer is  A: More than 180 degrees but less than 360 degrees*  

### AI Response: (may contain errors)  

In a push-pull, Class AB amplifier, each active element (transistor or tube) conducts for more than half of the signal cycle but less than the entire cycle. This is why the correct answer is:

**A: More than 180 degrees but less than 360 degrees**

### Explanation:

1. **Correct Answer: More than 180 degrees but less than 360 degrees**
   - In a Class AB amplifier, each active element conducts for slightly more than 180 degrees of the signal cycle. This means that each element is active for more than half of the waveform but not the entire waveform. This allows for reduced distortion compared to Class B amplifiers, where each element conducts exactly 180 degrees, and improved efficiency compared to Class A amplifiers, where each element conducts for the entire cycle.

2. **Why Other Choices Are Incorrect:**
   - **B: Exactly 180 degrees**
     - This describes a Class B amplifier, where each active element conducts for exactly half of the signal cycle. This can lead to crossover distortion, which is minimized in Class AB amplifiers.
   - **C: The entire cycle**
     - This describes a Class A amplifier, where each active element conducts for the full 360 degrees of the signal cycle. Class A amplifiers have high linearity but are less efficient than Class AB amplifiers.
   - **D: Less than 180 degrees**
     - This describes a Class C amplifier, where each active element conducts for less than half of the signal cycle. Class C amplifiers are used for RF applications where efficiency is more important than linearity.

### Summary:

- **Class AB Amplifier:** Conducts for more than 180 degrees but less than 360 degrees, balancing efficiency and linearity.
- **Class B Amplifier:** Conducts for exactly 180 degrees, leading to potential crossover distortion.
- **Class A Amplifier:** Conducts for the entire 360 degrees, offering high linearity but low efficiency.
- **Class C Amplifier:** Conducts for less than 180 degrees, used mainly in RF applications for high efficiency.