Question

why are networks of cables not used to send information from a remote control to a television?
a. cables slow down the speed at which information is communicated.
b. infrared radiation cannot travel through cables.
c. microwaves cannot travel through cables.
d. the information needs to travel only a short distance.

Explanation:

Remote controls use infrared radiation. Infrared radiation can travel through the air over a short distance (typically a few meters in the case of a TV remote - control to TV setup). Using cables would be cumbersome as it would restrict the movement of the remote control. Also, for the short - range communication (a few meters) between a remote control and a TV, wireless (infrared in this case) is more practical.

• Option A: Cables do not slow down the speed of information communication in a way that would be a problem for a remote - control to TV connection. Electrical signals in cables travel at a significant fraction of the speed of light.
• Option B: Infrared radiation is not the type of signal that would be sent through a cable for a remote - control to TV connection. Remote controls use infrared for wireless short - range communication.
• Option C: Microwaves are not used in the standard remote - control to TV communication. Remote controls use infrared.

Answer:

D. The information needs to travel only a short distance.