Which two sources cause interference for Wi-Fi networks? (Choose two).
Correct Answer: A,C
Windows can actually block your WiFi signal. How? Because the signals will be reflected by the glass.
Some new windows have transparent films that can block certain wave types, and this can make it harder for your WiFi signal to pass through. Tinted glass is another problem for the same reasons. They sometimes contain metallic films that can completely block out your signal. Mirrors, like windows, can reflect your signal. They`re also a source of electromagnetic interference because of their metal backings.
Reference: https://dis-dot-dat.net/what-materials-can-block-a-wifi-signal/ An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. WiFi operates in the gigahertz microwave band. The FCC has strict regulations on RFI (radio frequency interference) from all sorts of things, including light bulbs -> Incandesent lights do not interfere Wi-Fi networks.
Note:
+ Many baby monitors operate at 900MHz and won`t interfere with Wi-Fi, which uses the 2.4GHz band.
+ DECT cordless phone 6.0 is designed to eliminate wifi interference by operating on a different frequency. There is essentially no such thing as DECT wifi interference.