*Question E9B06:
What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?*  

*Correct Answer is  C: 7.5 degrees*  

### AI Response: (may contain errors)  

To determine the elevation angle of peak response in an antenna radiation pattern, you need to analyze the pattern shown in Figure E9-2. Since we don't have the actual figure here, let's discuss how you would typically approach this problem:

1. **Understanding the Radiation Pattern**:  
   The radiation pattern of an antenna is a graphical representation of the relative strength of the radio waves emitted by the antenna in different directions. The peak response is the direction in which the antenna radiates the strongest signal.

2. **Elevation Angle**:  
   The elevation angle is the angle above the horizontal plane. In the context of the radiation pattern, it is the angle at which the maximum radiation occurs.

3. **Correct Answer: 7.5 degrees (Choice C)**:  
   - The correct answer is 7.5 degrees because, in the given figure (which we assume you have access to during the exam), the peak of the radiation pattern is at this angle above the horizontal plane.
   - This is typically determined by observing the point on the pattern where the radiation intensity is highest.

4. **Why Other Choices Are Incorrect**:  
   - **45 degrees (Choice A)**: This angle is too high for the peak response in most typical antenna patterns, especially those designed for low-angle radiation.
   - **75 degrees (Choice B)**: This angle is even higher and unlikely to be the peak response for antennas designed for terrestrial communication.
   - **25 degrees (Choice D)**: While more plausible than the higher angles, it is still not the peak response as indicated by the figure.

5. **General Rule of Thumb**:  
   - For antennas used in terrestrial communication, the peak response is often at a lower elevation angle to maximize coverage over the Earth's surface.
   - Always refer to the specific radiation pattern provided in the exam to determine the correct angle.

By understanding how to read and interpret radiation patterns, you can accurately determine the elevation angle of peak response.