1. An antenna is used to:
(A) Transmit or receive electromagnetic waves
(B) Convert DC to AC
(C) Amplify electrical signals
(D) Filter unwanted frequencies
2. The part of a communication system that radiates electromagnetic waves is called:
(A) Antenna
(B) Oscillator
(C) Modulator
(D) Amplifier
3. The ability of an antenna to focus energy in a particular direction is called:
(A) Directivity
(B) Bandwidth
(C) Impedance
(D) Efficiency
4. The ratio of power radiated in a given direction to the average power is called:
(A) Gain
(B) Polarization
(C) Wavelength
(D) Bandwidth
5. The polarization of an antenna refers to:
(A) Orientation of the electric field of the radiated wave
(B) Direction of current in the antenna
(C) Antenna resistance
(D) Frequency range
6. The most commonly used antenna for radio broadcasting is the:
(A) Dipole antenna
(B) Loop antenna
(C) Horn antenna
(D) Parabolic antenna
7. A half-wave dipole antenna has a length equal to:
(A) Half of the wavelength of the signal
(B) Twice the wavelength
(C) Equal to wavelength
(D) Quarter of the wavelength
8. The directional antenna used for long-distance communication is the:
(A) Parabolic reflector antenna
(B) Loop antenna
(C) Whip antenna
(D) Patch antenna
9. The antenna used in satellite communication is generally a:
(A) Parabolic dish antenna
(B) Loop antenna
(C) Ferrite antenna
(D) Yagi-Uda antenna
10. The antenna used in TV receivers is commonly a:
(A) Yagi-Uda antenna
(B) Horn antenna
(C) Helical antenna
(D) Dish antenna
11. The efficiency of an antenna is the ratio of:
(A) Power radiated to total input power
(B) Total input power to power radiated
(C) Power reflected to incident power
(D) Power lost to power radiated
12. The region far from the antenna where radiation is uniform is called:
(A) Far field region
(B) Near field region
(C) Reactive field region
(D) Induction zone
13. The bandwidth of an antenna refers to:
(A) Range of frequencies over which it operates effectively
(B) Frequency of resonance
(C) Frequency of transmission
(D) Difference between gain and directivity
14. The main advantage of a parabolic reflector antenna is:
(A) High gain and directivity
(B) Low efficiency
(C) Small size
(D) Omnidirectional radiation
15. The polarization of satellite communication antennas is usually:
(A) Circular
(B) Linear
(C) Horizontal
(D) Vertical
16. A waveguide is used to:
(A) Guide electromagnetic waves from one point to another
(B) Convert electrical signals to optical signals
(C) Filter out noise
(D) Amplify RF signals
17. The transmission medium that uses total internal reflection is:
(A) Optical fiber
(B) Coaxial cable
(C) Twisted pair
(D) Waveguide
18. The main advantage of optical fiber communication is:
(A) High bandwidth and low signal loss
(B) High power requirement
(C) Heavy weight and large size
(D) High noise interference
19. Coaxial cables are commonly used for:
(A) Cable television and broadband
(B) Optical communication
(C) Satellite uplink
(D) Microwave transmission
20. Twisted pair cables are mainly used in:
(A) Telephone networks and LANs
(B) Optical networks
(C) Satellite communication
(D) Microwave systems
21. The main disadvantage of coaxial cable is:
(A) Signal attenuation over long distances
(B) High noise immunity
(C) Low bandwidth
(D) Large size
22. The loss of signal power during transmission is known as:
(A) Attenuation
(B) Reflection
(C) Refraction
(D) Modulation
23. In a waveguide, electromagnetic waves propagate in:
(A) Transverse electric and magnetic modes
(B) Longitudinal modes only
(C) Circular modes only
(D) Scalar modes
24. The impedance of free space is approximately:
(A) 377 ohms
(B) 100 ohms
(C) 50 ohms
(D) 200 ohms
25. A horn antenna is often used as:
(A) Feed element for parabolic reflector antennas
(B) Low-frequency transmitter
(C) Omnidirectional receiver
(D) Broadband amplifier
26. The ground wave propagation is significant for:
(A) Low-frequency signals
(B) High-frequency signals
(C) Microwave signals
(D) Optical signals
27. Sky wave propagation is mainly used for:
(A) Long-distance HF communication
(B) Microwave links
(C) Optical fiber transmission
(D) Local Wi-Fi networks
28. Line-of-sight communication is used in:
(A) Microwave and satellite systems
(B) AM radio
(C) Underwater communication
(D) Low-frequency transmission
29. The phenomenon of wave bending around obstacles is known as:
(A) Diffraction
(B) Reflection
(C) Refraction
(D) Interference
30. The transmission medium with the least signal interference is:
(A) Optical fiber
(B) Coaxial cable
(C) Twisted pair
(D) Waveguide