Ham Radio General Class Test FREE Ham Radio General Class Test Radio Wave Propagation Questions and Answers 2

Question 1

What is the primary cause of ionospheric absorption of HF radio signals?

Accepted Answer

D-layer ionization during daylight hours

Answer

The D layer, which forms during daylight, absorbs HF signals rather than refracting them, particularly at lower HF frequencies.

Question 2

Which propagation mode is most commonly used for VHF communications beyond line-of-sight during certain weather conditions?

Accepted Answer

Tropospheric ducting

Answer

Tropospheric ducting occurs when temperature inversions in the lower atmosphere bend VHF and UHF signals beyond the normal horizon.

Question 3

What does the term 'Maximum Usable Frequency' (MUF) refer to in HF propagation?

Accepted Answer

The highest frequency that will be refracted back to Earth by the ionosphere for a given path

Answer

The MUF is the highest frequency at which a radio wave can be refracted by the ionosphere back to Earth for a specific transmission path at a given time.

Question 4

What effect does solar flux index (SFI) have on HF propagation?

Accepted Answer

Higher SFI generally improves HF propagation on higher frequency bands

Answer

A higher solar flux index indicates greater solar radiation, which increases ionospheric ionization and supports propagation at higher HF frequencies.

Question 5

What is the approximate speed at which radio waves travel through free space?

Accepted Answer

300,000,000 meters per second

Answer

Radio waves travel at the speed of light, approximately 300,000,000 meters per second (3 x 10^8 m/s) in free space.

Ham Radio General Class Test Practice Test

Ham Radio General Class Test Practice Test

Ham Radio General Class Test FREE Ham Radio General Class Test Radio Wave Propagation Questions and Answers 2