CCNP ENCOR - cap 17 a 19

Two transmitters are each operating with a transmit power level of 100 mW. When you compare the two absolute power levels, what is the difference in dB?

• 0 dB

• 20 dB

• 100 dB

• You can’t compare power levels in dB.

A transmitter is configured to use a power level of 17 mW. One day it is reconfigured to transmit at a new power level of 34 mW. How much has the power level increased, in dB?

• 0 dB

• 2 dB

• 3 dB

• 17 dB

• None of these answers are correct; you need a calculator to figure this out.

Transmitter A has a power level of 1 mW, and transmitter B is 100 mW. Compare transmitter B to A using dB, and then identify the correct answer from the following choices.

• 0 dB

• 1 dB

• 10 dB

• 20 dB

• 100 dB

A transmitter normally uses an absolute power level of 100 mW. Through the course of needed changes, its power level is reduced to 40 mW. What is the power-level change in dB?

• 2.5 dB

• 4 dB

• –4 dB

• –40 dB

• None of these answers are correct; where is that calculator?

Consider a scenario with a transmitter and a receiver that are separated by some distance. The transmitter uses an absolute power level of 20 dBm. A cable connects the transmitter to its antenna. The receiver also has a cable connecting it to its antenna. Each cable has a loss of 2 dB. The transmitting and receiving antennas each have a gain of 5 dBi. What is the resulting EIRP?

• 20 dBm

• +23 dBm

• +26 dBm

• +34 dBm

• None of these answers are correct.

A receiver picks up an RF signal from a distant transmitter. Which one of the following represents the best signal quality received? Sample values are given in parentheses.

• Low SNR (10 dB), low RSSI (–75 dBm)

• High SNR (30 dB), low RSSI (–75 dBm)

• Low SNR (10 dB), high RSSI (–55 dBm)

• High SNR (30 dB), high RSSI (–55 dBm)

Which one of the following is the primary cause of free space path loss?

• Spreading

• Absorption

• Humidity levels

• Magnetic field decay

Which one of the following has the shortest effective range in free space, assuming that the same transmit power level is used for each?

• An 802.11g device

• An 802.11a device

• An 802.11b device

• None of these answers are correct.

QAM alters which of the following aspects of an RF signal? (Choose two.)

• Frequency

• Amplitude

• Phase

• Quadrature

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 do to improve the signal quality along the way?

• Aggregate more channels

• Use more radio chains

• Switch to a more complex modulation scheme

• Switch to a less complex modulation scheme