*Question G3B10:
What is the approximate maximum distance along the Earth’s surface normally covered in one hop using the E region?*  

*Correct Answer is  B: 1,200 miles*  

### AI Response: (may contain errors)  

The correct answer to the question about the maximum distance covered in one hop using the E region is 1,200 miles. Here's the explanation:

1. **Why the correct answer is correct:**
   - The E region of the ionosphere typically reflects radio waves at frequencies between about 30 MHz and 300 MHz. The maximum distance for a single hop in this region is generally around 1,200 miles (approximately 2,000 kilometers). This distance is influenced by factors such as frequency, time of day, and solar activity, but 1,200 miles is a commonly accepted average for E region propagation.

2. **Why the other choices are incorrect:**
   - **A: 180 miles** - This distance is too short for E region propagation. It may be more applicable to lower frequency bands or other propagation modes.
   - **C: 2,500 miles** - This distance exceeds the typical range for a single hop in the E region. While some conditions might allow for longer distances, 2,500 miles is more characteristic of F region propagation.
   - **D: 12,000 miles** - This distance is far beyond what the E region can support in a single hop. Such distances are more relevant to satellite communications or long-distance F region propagation.

3. **Useful formulas or rules of thumb:**
   - A general rule of thumb for estimating the maximum distance for a single hop in the ionosphere is:
     $$ D \approx 1,200 \text{ miles} $$
   - This is a simplified approximation and can vary based on the specific conditions of the ionosphere at any given time.

In summary, the E region typically supports a maximum distance of about 1,200 miles for one hop, making it the correct answer for this question.