1. Which factor significantly affects signal propagation over water or flat open areas?
a) Foliage loss
b) Terrain elevation
c) Atmospheric conditions
d) Humidity levels
Answer: b) Terrain elevation
Explanation: Signal propagation over water or flat open areas is greatly influenced by terrain elevation. Flat terrain allows signals to travel further with minimal obstruction compared to areas with varying terrain elevations.
2. What is the primary cause of signal attenuation in areas with dense foliage?
a) Reflection
b) Absorption
c) Refraction
d) Diffraction
Answer: b) Absorption
Explanation: Dense foliage absorbs a significant portion of the signal energy, leading to signal attenuation in such areas.
3. Which type of propagation is predominant in near-line-of-sight communication?
a) Ground wave propagation
b) Sky wave propagation
c) Space wave propagation
d) Tropospheric scatter propagation
Answer: c) Space wave propagation
Explanation: Near-line-of-sight communication primarily relies on space wave propagation, where the signal travels directly from the transmitting antenna to the receiving antenna without significant reflection or diffraction.
4. What is the primary mechanism of signal loss in long-distance propagation?
a) Absorption
b) Reflection
c) Scattering
d) Path loss
Answer: d) Path loss
Explanation: Path loss is the primary mechanism of signal attenuation over long distances due to factors such as free space loss, atmospheric absorption, and terrain effects.
5. Which parameter significantly influences the coverage area of a cell site antenna?
a) Antenna material
b) Antenna gain
c) Antenna polarization
d) Antenna impedance
Answer: b) Antenna gain
Explanation: Antenna gain determines the directionality and effective radiated power of the antenna, thereby influencing the coverage area of a cell site.
6. In the context of cell site antennas, what does antenna gain represent?
a) Ability to resist interference
b) Ability to amplify received signals
c) Ability to focus radiation in specific directions
d) Ability to synchronize with neighboring cells
Answer: c) Ability to focus radiation in specific directions
Explanation: Antenna gain represents the ability of the antenna to concentrate radiated energy in specific directions, thereby enhancing signal strength in those directions.
7. What is a unique situation where cell site antennas may be subjected to multipath interference?
a) Urban environments
b) Mountainous regions
c) Coastal areas
d) Suburban neighborhoods
Answer: a) Urban environments
Explanation: Urban environments with tall buildings and structures often create multipath interference, where signals reflect off surfaces and arrive at the receiver via multiple paths, causing signal distortion.
8. Which factor is crucial in determining the efficiency of mobile antennas?
a) Antenna impedance
b) Antenna material
c) Antenna size
d) Antenna orientation
Answer: c) Antenna size
Explanation: The size of the mobile antenna significantly affects its efficiency in transmitting and receiving signals, with larger antennas generally providing better performance.
9. What is the relationship between antenna gain and antenna pattern?
a) Inverse relationship
b) Direct relationship
c) No relationship
d) Exponential relationship
Answer: b) Direct relationship
Explanation: Antenna gain and antenna pattern have a direct relationship, meaning higher gain antennas typically have narrower radiation patterns focused in specific directions.
10. In mobile-to-mobile propagation, what phenomenon is primarily responsible for signal fading and fluctuation?
a) Reflection
b) Refraction
c) Doppler effect
d) Scattering
Answer: c) Doppler effect
Explanation: In mobile-to-mobile propagation, the Doppler effect causes signal fading and fluctuation as a result of relative motion between the transmitting and receiving antennas.