Antenna and Wave Propagation – MCQs

By: Prof. Dr. Fazal Rehman | Last updated: April 22, 2025

1. : What is the main function of an antenna?
(A) Store electrical energy
(B) Convert electrical signals into electromagnetic waves
(C) Amplify the signal
(D) Rectify the signal

2. : Which parameter of an antenna defines its ability to direct radiated power in a specific direction?
(A) Gain
(B) Bandwidth
(C) Efficiency
(D) Impedance

3. : The unit of antenna gain is:
(A) Watt
(B) dB
(C) Ohm
(D) Volt

4. : Which type of antenna is used for satellite communication?
(A) Yagi-Uda
(B) Dipole
(C) Parabolic dish
(D) Loop

5. : Which frequency band is suitable for sky wave propagation?
(A) UHF
(B) VHF
(C) HF
(D) SHF

6. : What is the polarization of an electromagnetic wave?
(A) Direction of wave propagation
(B) Direction of electric field
(C) Direction of magnetic field
(D) Direction of antenna gain

7. : Which antenna is most commonly used in TV reception?
(A) Dipole antenna
(B) Loop antenna
(C) Yagi-Uda antenna
(D) Horn antenna

8. : The efficiency of an antenna is defined as:
(A) Radiated power/Input power
(B) Input power/Radiated power
(C) Reflected power/Incident power
(D) Gain × Bandwidth

9. : Which of the following is not a method of wave propagation?
(A) Ground wave
(B) Sky wave
(C) Space wave
(D) Pulse wave

10. : What is the typical impedance of a half-wave dipole antenna?
(A) 75 ohms
(B) 50 ohms
(C) 73 ohms
(D) 100 ohms

11. : Which layer of the atmosphere reflects HF waves back to Earth?
(A) Troposphere
(B) Ionosphere
(C) Stratosphere
(D) Mesosphere

12. : The ratio of maximum radiation intensity to the average radiation intensity is called:
(A) Beamwidth
(B) Directivity
(C) Efficiency
(D) Radiation pattern

13. : What is the purpose of a balun in antenna systems?
(A) Increase gain
(B) Balance impedance
(C) Reduce size
(D) Amplify signal

14. : In wave propagation, the ground wave follows:
(A) The ionosphere
(B) The stratosphere
(C) The curvature of the Earth
(D) A straight line

15. : Which wave propagation is dominant above 30 MHz?
(A) Sky wave
(B) Ground wave
(C) Space wave
(D) Surface wave

16. : What kind of antenna is a half-wave dipole?
(A) Omnidirectional
(B) Directional
(C) Bidirectional
(D) Unidirectional

17. : Radiation resistance is associated with:
(A) Power loss due to resistance
(B) Power radiated by the antenna
(C) Antenna bandwidth
(D) VSWR

18. : Which of the following antennas is used at microwave frequencies?
(A) Dipole
(B) Loop
(C) Horn
(D) Whip

19. : What is VSWR in antenna terminology?
(A) Voltage Surface Wave Ratio
(B) Voltage Standing Wave Ratio
(C) Very Strong Wave Radiation
(D) Voltage Series Wave Reflection

20. : An isotropic antenna is:
(A) Ideal antenna with directional radiation
(B) Real antenna with uniform radiation
(C) Ideal antenna with uniform radiation in all directions
(D) Directional antenna with high gain

21. : The ionosphere mainly affects which type of waves?
(A) Sound waves
(B) HF radio waves
(C) VHF television waves
(D) Light waves

22. : In antenna arrays, the pattern of radiation depends on:
(A) Individual antenna size
(B) Number and spacing of elements
(C) Cable length
(D) Weather conditions

23. : What is the wavelength of a 300 MHz signal?
(A) 0.1 m
(B) 1 m
(C) 10 m
(D) 100 m

24. : What is the beamwidth of an antenna?
(A) Width of the physical antenna
(B) Angle between half-power points in the radiation pattern
(C) Distance between antenna terminals
(D) Diameter of the radiation circle

25. : Which antenna is commonly used in mobile phones?
(A) Dipole
(B) Helical
(C) Whip
(D) Patch