# Objective Questions on Wave Propagation

## Objective Questions on Wave Propagation

Objective Questions on Wave Propagation, MCQ on Wave Propagation, MCQ on space wave propagation, electromagnetic wave propagation MCQ, antenna and wave propagation MCQs, multiple-choice questions on radiation and propagation

1. Ground wave propagation is used when:
• f is in the UHF range
• f is in the microwave range
• f is in LF range
• f is in VHF range

Answer: f is in LF range

2. Wave unaffected by night or day is

• ground wave
• skywave
• space wave
• tropospheric wave

3. When an EM wave propagates from air into the ionosphere, its velocity

• decreases
• increases
• remains the same
• reduces to zero

4. During day-time the ionospheric layer that does not exist is

• F
• F1
• F2
• D

5. EM waves of UHF range normally propagate by means of

• ground waves
• space waves
• sky waves
• surface waves

6. The absorption of EM waves by the atmosphere depends on

• the distance of the transmitter
• their frequency
• the polarization of the waves
• strength of EM wave

7. Short-waves for long distance communication depend on

• ionospheric waves
• ground waves
• direct waves
• space waves

8. Troposcatter propagation is used at frequency range of

• VHF only
• VLF only
• MF only
• UHF and VHF

9. The relative permittivity of ionospheric layer is

• \epsilon_{r}=\left ( 1-\frac{81N}{f^{2}} \right )
• \epsilon_{r}=\sqrt{1-\frac{81N}{f^{2}}}
• \epsilon_{r}=\left ( 1-\frac{f^{2}}{81N} \right )
• \epsilon_{r}=9\sqrt{N}

Answer: \epsilon_{r}=\left ( 1-\frac{81N}{f^{2}} \right )

10. If an EM wave whose frequency is 30 MHz is incident with an angle of 60°. MUF is

• 60 MHz
• 20 MHz
• 30 MHz
• 10 MHz

11. Critical frequency of the ionospheric layer is

• f_{c}=81\sqrt{N_{max}}
• f_{c}=81{N_{max}}
• f_{c}=9\sqrt{N_{max}}
• f_{c}=9N_{max}

12. For radio wave propagation, fresh water is considered to be

• very poor
• poor
• very good
• average

13. For radio wave propagation, cities are considered to be

• poor
• very poor
• very good
• good

14. Radio horizon distance for standard atmosphere when ht = 50 m and hr is 5 m is

• 38.37 km
• 38.37 miles
• 383.7 km
• 383.7 miles