## 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**F*_{1}*F*_{2}*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 *h _{t}* = 50 m and

*h*is 5 m is

_{r}- 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/m^{3} is

- 2.777 × 10
^{10} - 27.77 × 10
^{10} - 0.2777 × 10
^{10} - 277.7 × 10
^{10}

**Answer:** 2.777 × 10^{10}