CWS CWS Basic RF Principles 3

Question 1

What is the SNR of a signal received at -65 dBm with a noise floor of -95 dBm?

Accepted Answer

30 dB

Answer

SNR = Signal level − Noise floor = −65 dBm − (−95 dBm) = 30 dB.

Question 2

Which multipath effect causes rapid, short-term fluctuations in received signal strength as a mobile client moves?

Accepted Answer

Fast fading (Rayleigh fading)

Answer

Fast fading (Rayleigh fading) results from constructive and destructive interference of multipath components as the receiver moves even small distances.

Question 3

A cable with 3 dB of loss cuts transmitted power by approximately:

Accepted Answer

Half

Answer

3 dB of loss corresponds to a power ratio of 2, so 3 dB loss means half the power is lost.

Question 4

Which 802.11 band is generally more susceptible to interference from microwave ovens?

Accepted Answer

2.4 GHz

Answer

Microwave ovens operate near 2.45 GHz and directly overlap the 2.4 GHz Wi-Fi band.

Question 5

What is the primary purpose of antenna diversity in wireless systems?

Accepted Answer

To mitigate multipath fading by selecting or combining signals from multiple antennas

Answer

Antenna diversity uses multiple antennas to combat multipath fading by selecting the best signal or combining signals.

CWS Exam Practice Test

CWS Exam Practice Test

CWS CWS Basic RF Principles 3