CWNA: Certified Wireless Network Administrator v107 — Question 42

When using a spectrum analyzer to look for non-Wi-Fi interference sources, you notice significant interference across the entire 2.4 GHz band (not on a few select frequencies) within the desktop area of a users workspace, but the interference disappears quickly after just 2 meters. What is the most likely cause of this interference?

Answer options

• A. USB 3 device in the user’s work area
• B. Bluetooth devices in the user’s work area
• C. Excess RF energy from a nearby AP
• D. Unintentional radiation from the PC power supply

Correct answer: D

Explanation

The correct answer is D because unintentional radiation from the PC power supply can create a broad spectrum of interference that diminishes quickly with distance. Options A and B are less likely since their interference typically affects specific frequencies rather than the entire band, and option C suggests interference from an external source, which would not disappear so quickly.