Wireless Technology – Quiz 2

• Question 1
1 out of 1 points

Which one of the following best describes the effect that a building material has as an RF signal passes through a wall?
Selected Answer: Absorption

• Question 2
1 out of 1 points

Suppose that you place a new 802.11 transmitter in a building, but notice that there are other signals already coming from transmitters in the same general area. To avoid interference problems, how much greater should your transmitter’s signal be above all of the others?
Selected Answer: +20 dBm

• Question 3
2 out of 2 points

An omnidirectional antenna usually has which of the following characteristics? (Choose two.)
Large beamwidth
Low gain

• Question 4
1 out of 1 points

A dipole antenna is connected to a transmitter. You would like to leverage the directional quality of the antenna. Based on the radiation pattern of the antenna, what would happen if you orient the antenna such that its cylindrical shape points directly at a distant receiver?
Selected Answer: The receiver would pick up a weaker signal.

• Question 5
1 out of 1 points

Suppose that an 802.11a device moves away from a transmitter. As the signal strength decreases, which one of the following might the device or the transmitter change to improve the signal quality along the way?
Selected Answer: Switch to a less-complex modulation scheme

• Question 6
2 out of 2 points

Which two of the following plots are used to show the radiation pattern of an antenna?
H plane
E plane

• Question 7
1 out of 1 points

Which one of the following has the shortest effective range in free space, assuming that the same transmit power level is used for each?
Selected Answer: An 802.11a device

• Question 8
1 out of 1 points

The orientation of an electromagnetic wave is best described by which one of the following?
Selected Answer: Polarization

• Question 9
1 out of 1 points

When RF signals are reflected by objects in a building, which one of the following best describes the result that might be experienced at a receiver?
Selected Answer: Multipath

• Question 10
1 out of 1 points

Which one of the following is not true about a lightning arrestor?
Selected Answer: It protects against lightning strikes on an antenna.

• Question 11
1 out of 1 points

An existing transmitter in your office sends its signal on 2.4-GHz channel 1. Suppose that someone in a neighboring office sets up a new wireless router. He notices your signal on channel 1, so he chooses channel 2 instead. Which one of the following might adversely affect the wireless operation?
Selected Answer: Neighboring channel interference

• Question 12
1 out of 1 points

Which one of the following is the primary cause of free space path loss?
Selected Answer: Spreading

• Question 13
1 out of 1 points

Which one of the following antennas would probably have the greatest gain?
Selected Answer: Dish

• Question 14
1 out of 1 points

An 802.11 transmitter is configured to send a signal on channel11. Someone reports a problem receiving the signal, so you investigate and find a second transmitter broadcasting on channel11. Which one of the following best describes the problem?
Selected Answer: Co-channel interference

• Question 15
1 out of 1 points

A Cisco dipole antenna is mounted so that it points straight upward and has a radiation pattern that extends far outward horizontally. Which one of the following best describes the antenna’s polarization?
Selected Answer: Vertical polarization

• Question 16
1 out of 1 points

A certain Cisco wireless access point model has antennas that are hidden inside the case. Which one of the following describes the antennas?
Selected Answer: Omnidirectional antennas

• Question 17
1 out of 1 points

Which one of the following is the best strategy for avoiding interference between neighboring channels in the 2.4-GHz band?
Selected Answer: Use only channels that are spaced five numbers apart, beginning with channel 1

• Question 18
1 out of 1 points

Which one of the following is another name for the H plane radiation pattern?
Selected Answer: Azimuth plane

• Question 19
1 out of 1 points

Which one of the following best describes the purpose of the first Fresnel zone?
Selected Answer: The area around a signal path that should be kept clear of any obstructions

• Question 20
1 out of 1 points

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?
Selected Answer: Beamwidth