*Question G8C14:
Which of the following describes a waterfall display?*  

*Correct Answer is  C: Frequency is horizontal, signal strength is intensity, time is vertical*  

### AI Response: (may contain errors)  

A waterfall display is a visual representation used in radio communications to show how signals change over time. 

### Correct Answer Explanation:
- **Correct Answer: Frequency is horizontal, signal strength is intensity, time is vertical.**
  - In a waterfall display:
    - The **horizontal axis** represents **frequency**. This allows you to see which frequencies are active.
    - The **vertical axis** represents **time**. As time progresses, the display updates to show how signals change.
    - The **intensity** (or color) of the display indicates the **signal strength**. Brighter or more intense colors represent stronger signals.

### Why Other Choices Are Incorrect:
- **Choice A: Frequency is horizontal, signal strength is vertical, time is intensity.**
  - This is incorrect because it misplaces the axes. Time should be vertical, not intensity.

- **Choice B: Frequency is vertical, signal strength is intensity, time is horizontal.**
  - This is incorrect because it reverses the axes for frequency and time. Frequency should be horizontal.

- **Choice C: Frequency is horizontal, signal strength is intensity, time is vertical.**
  - This choice is actually correct, but it does not match the wording of the correct answer provided. It describes the same relationship but is not the answer format expected.

### Summary:
- A waterfall display effectively shows how signals vary over time, with frequency on the horizontal axis, time on the vertical axis, and signal strength represented by intensity. 

This understanding is crucial for interpreting signals in real-time and is a key concept for the Extra Class exam.