- Home
- Networking
- CCNA Wireless
36.
Which one of the following best describes the effect that a building material has as an
RF signal passes through a wall?
- A.Reflection
- B.Refraction
- C.Diffraction
- D.Absorption
- E.Multipath
- Answer & Explanation
- Report
Answer : [D]
Explanation :
Explanation :
| As a signal passes through a wall, the building material absorbs some of the RF energy, reducing the signal strength by some amount. |
37.
Which one of the following best describes the first Fresnel zone?
- A.The area covered by one transmitter on a channel
- B.The area around a signal path that should be kept clear of any obstructions
- C.The area around a signal path that is blocked by the earth’s curvature
- D.The area around a transmitter that represents the range of a signal
- Answer & Explanation
- Report
Answer : [B]
Explanation :
Explanation :
| The first Fresnel zone is an elliptical area along the length of a signal path that should be kept free of obstructions. When an object extends into a significant portion of the Fresnel zone, the signal can be diffracted and distorted. |
38.
Which two of the following plots are used to show the radiation pattern of an
antenna?
- A.A plane
- B.E plane
- C.XY plane
- D.H plane
- E.YZ-plane
- Answer & Explanation
- Report
Answer : [B and D]
Explanation :
Explanation :
| The E and H plane plots are used to show a side view and a top-down view, respectively, with the antenna in the center of the plots. |
39.
Which one of the following is another name for the H plane radiation pattern?
- A.Horizon plane
- B.Azimuth plane
- C.Heat map
- D.Lateral plane
- Answer & Explanation
- Report
Answer : [B]
Explanation :
Explanation :
| The H plane is also known as the azimuth plane because measurements are taken at every azimuth angle around the base of the antenna. |
40.
Which one of the following answers correctly identifies the antenna parameter that is
measured at 3 dB below the strongest point on a radiation pattern plot?
- A.Half life
- B.Decay point
- C.Cut off point
- D.Beamwidth
- E.Sensitivity
- Answer & Explanation
- Report
Answer : [D]
Explanation :
Explanation :
| The beamwidth is the angle measured between the two points on a radiation pattern plot that are 3 dB below the maximum. |
|
|
||||||||||||||||||||||||||||
