*Question E3B10:
What is the effect of chordal-hop propagation?*  

*Correct Answer is  A: The signal experiences less loss compared to multi-hop propagation, which uses Earth as a reflector*  

### AI Response: (may contain errors)  

Chordal-hop propagation refers to a type of radio wave propagation that occurs when signals bounce off the ionosphere at a steep angle, allowing them to travel along the ionospheric layer rather than reflecting off the Earth. 

### Correct Answer Explanation:
- **A: The signal experiences less loss compared to multi-hop propagation, which uses Earth as a reflector.**  
  This is correct because chordal-hop propagation typically results in lower signal loss. In multi-hop propagation, signals reflect off the Earth, which can introduce additional losses due to ground absorption and other factors. Chordal-hop propagation, on the other hand, allows signals to travel more efficiently along the ionosphere, minimizing these losses.

### Incorrect Answer Explanations:
- **B: The MUF for chordal-hop propagation is much lower than for normal skip propagation.**  
  This is incorrect because the Maximum Usable Frequency (MUF) for chordal-hop propagation is generally higher than for normal skip propagation. Chordal-hop can utilize higher frequencies effectively due to the steep angle of incidence, which allows for better propagation characteristics.

- **C: Atmospheric noise is reduced in the direction of chordal-hop propagation.**  
  This statement is not accurate. While chordal-hop propagation can be more efficient, it does not inherently reduce atmospheric noise. Atmospheric noise is influenced by various factors, including weather and solar activity, and is not specifically reduced by the propagation method.

- **D: Signals travel faster along ionospheric chords.**  
  This is misleading. The speed of radio waves in the ionosphere is determined by the medium (ionized gas) and is not significantly different for chordal-hop propagation compared to other types of propagation. The speed of light in a vacuum is approximately $3 \times 10^8$ m/s, and while it can be affected by the ionosphere, the propagation method does not change this fundamental speed.

### Summary:
- Chordal-hop propagation is advantageous due to lower signal loss compared to multi-hop propagation.
- The MUF is higher for chordal-hop, and atmospheric noise is not reduced by this method.
- Signal speed remains consistent, governed by the properties of the medium rather than the propagation method.

This understanding will help you answer questions related to propagation methods effectively on the Extra Class exam.