Deep Dive: E3C06
The correct answer is A: It is approximately 15 percent farther. How does the VHF/UHF radio horizon compare to the geographic horizon is that it is approximately 15 percent farther. Radio waves bend slightly due to atmospheric refraction, extending the radio horizon. For amateur radio operators, this is important for VHF/UHF operation. Understanding this helps when planning VHF/UHF contacts.
Why Other Answers Are Wrong
Option B: Incorrect. 20 percent nearer isn't correct - radio horizon is farther, not nearer. Nearer is wrong. Option C: Incorrect. 50 percent farther is too much - radio horizon is about 15 percent farther. 50 percent is too high. Option D: Incorrect. They're not approximately the same - radio horizon is about 15 percent farther. Same is wrong.
Exam Tip
VHF/UHF radio horizon vs geographic = approximately 15 percent farther. Think 'R'adio 'H'orizon = 'R'efraction 'H'elps (15% farther). Radio waves bend slightly due to atmospheric refraction, extending the radio horizon. Not nearer, not 50%, not same - just 15% farther.
Memory Aid
VHF/UHF radio horizon vs geographic = approximately 15 percent farther. Think 'R'adio 'H'orizon = '1'5% farther. Radio waves bend slightly due to atmospheric refraction, extending the radio horizon. Important for VHF/UHF operation.
Real-World Example
VHF/UHF radio horizon: It's approximately 15 percent farther than the geographic horizon. This is because atmospheric refraction bends radio waves slightly downward, extending the effective horizon. For example, if geographic horizon is 10 miles, radio horizon is about 11.5 miles. This is the comparison - radio horizon is 15% farther.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E3C
Reference: 2024-2028 Question Pool · E3 - Radio Wave Propagation
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E3C topic.