Ham Radio Technician Test Radio Wave Propagation & Modulation 2

Question 1

What effect does a temperature inversion in the atmosphere have on VHF radio waves?

Accepted Answer

It can cause signals to travel much farther than normal

Answer

It completely absorbs VHF signals

Answer

It reflects VHF back into space

Answer

It converts VHF to HF frequencies

Question 2

Which modulation mode is most commonly used for FM voice transmissions on VHF/UHF amateur bands?

Accepted Answer

Frequency modulation (FM)

Answer

Single sideband (SSB)

Answer

Amplitude modulation (AM)

Answer

Continuous wave (CW)

Question 3

What is the term for the lowest frequency that will be refracted back to Earth from the ionosphere at vertical incidence?

Accepted Answer

Critical frequency

Answer

Maximum usable frequency (MUF)

Answer

Skip frequency

Answer

Lowest usable frequency (LUF)

Question 4

Which ionospheric layer is primarily responsible for long-distance HF communication during daytime?

Accepted Answer

F2 layer

Answer

D layer

Answer

E layer

Answer

F1 layer

Question 5

What type of propagation allows a 10-meter signal to be received across the country with very low power during high solar activity?

Accepted Answer

F2 ionospheric propagation

Answer

Ground wave propagation

Answer

Sporadic-E propagation

Answer

Tropospheric ducting

Question 6

What is the deviation in an FM signal?

Accepted Answer

The amount the carrier frequency shifts above and below its center frequency

Answer

The rate at which the carrier frequency changes

Answer

The ratio of modulating signal amplitude to carrier amplitude

Answer

The bandwidth occupied by the sidebands

Question 7

Which band is most likely to support auroral propagation?

Accepted Answer

2 meters

Answer

160 meters

Answer

40 meters

Answer

630 meters