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
- 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
Answer: ground wave
3. When an EM wave propagates from air into the ionosphere, its velocity
- decreases
- increases
- remains the same
- reduces to zero
Answer: increases
4. During day-time the ionospheric layer that does not exist is
- F
- F1
- F2
- D
Answer: F
5. EM waves of UHF range normally propagate by means of
- ground waves
- space waves
- sky waves
- surface waves
Answer: space 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
Answer: their frequency
7. Short-waves for long distance communication depend on
- ionospheric waves
- ground waves
- direct waves
- space waves
Answer: ionospheric waves
8. Troposcatter propagation is used at frequency range of
- VHF only
- VLF only
- MF only
- UHF and VHF
Answer: 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
Answer: 60 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}
Answer: f_{c}=9\sqrt{N_{max}}
12. For radio wave propagation, fresh water is considered to be
- very poor
- poor
- very good
- average
Answer: poor
13. For radio wave propagation, cities are considered to be
- poor
- very poor
- very good
- good
Answer: poor
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
Answer: 38.37 km
15. If the critical frequency of the ionospheric layer is 1.5 MHz, the maximum electron density of the layer in electrons/m3 is
- 2.777 × 1010
- 27.77 × 1010
- 0.2777 × 1010
- 277.7 × 1010
Answer: 2.777 × 1010