CWNA RF Fundamentals & Signal Propagation

Question 1

What unit is used to express the ratio of transmitted power to received power in a wireless link?

Accepted Answer

dB

Answer

The decibel (dB) is a dimensionless unit used to express the ratio between two power levels in a wireless link.

Question 2

Which phenomenon causes a wireless signal to bend around obstacles and corners?

Accepted Answer

Diffraction

Answer

Diffraction causes radio waves to bend around edges and obstacles, allowing signals to reach areas not in direct line of sight.

Question 3

What is the free-space path loss (FSPL) most dependent on?

Accepted Answer

Frequency and distance

Answer

Free-space path loss increases with both higher frequency and greater distance between transmitter and receiver.

Question 4

Which multipath effect can cause partial or complete signal cancellation at the receiver?

Accepted Answer

Destructive interference

Answer

Destructive interference occurs when multipath signals arrive out of phase and combine to reduce or cancel the received signal.

Question 5

What percentage of the first Fresnel zone should be kept clear of obstructions for optimal link performance?

Accepted Answer

60%

Answer

Industry best practice requires at least 60% of the first Fresnel zone to be clear of obstructions to avoid significant signal degradation.

CWNA - Wireless Network Administrator Practice Test