Results
Q1. What name is given to the propagation of radio waves along the Earth’s surface?
Correct answer is B – Ground wave
Q2. Which layer of the ionosphere is primarily responsible for long-distance HF communication?
Correct answer is C – F layer
Q3. How many basic methods of radio propagation are commonly recognized?
Correct answer is B – Three
Q4. Which is a property of ground wave propagation?
Correct answer is A – Heavily affected by terrain and ground conductivity
Q5. What is the main method of propagation for VHF radio waves?
Correct answer is C – Line-of-sight (Space/Direct wave)
Q6. Why are VHF antennas mounted high?
Correct answer is B – Improve line-of-sight range
Q7. Ground waves are most effective at which frequency range?
Correct answer is A – VLF and LF
Q8. Which wave property allows radio waves to enter areas not in direct line-of-sight?
Correct answer is B – Diffraction
Q9. Which phenomenon enables radio waves to bend around obstacles?
Correct answer is C – Diffraction
Q10. What primarily causes “fading” in radio reception?
Correct answer is B – Interference of multiple signal paths
Q11. Which mode allows radio communication with satellites?
Correct answer is B – Space wave
Q12. What happens to signal strength of ground waves as frequency increases?
Correct answer is B – Decreases
Q13. Which mode is most effective for maritime long-distance communication?
Correct answer is C – Sky wave
Q14. What frequency range is best for sky wave (ionospheric) propagation?
Correct answer is B – 3–30MHz
Q15. What does the term “radio horizon” mean?
Correct answer is B – The distance where the direct radio wave drops below detection
Q16. Sky wave propagation is also known as:
Correct answer is B – Ionospheric propagation
Q17. What is radio frequency propagation?
Correct answer is B – How radio waves travel through different media
Q18. What is the “skip distance” in radio propagation?
Correct answer is B – Minimum distance from transmitter where sky wave returns to Earth
Q19. What is the primary factor limiting line-of-sight radio communication?
Correct answer is B – Earth’s curvature
Q20. What is “attenuation” in radio propagation?
Correct answer is B – Decrease in signal strength as it travels
