Question

1. what wavelength is used by a remote to change a television channel?

○ x-ray
○ ultraviolet
○ infrared
○ microwave

Explanation:

TV remotes use infrared (IR) waves to transmit signals. X - rays are for medical imaging, ultraviolet for sterilization/sunlight, microwaves for cooking/communication. IR is ideal for short - range remote control.

Answer:

C. infrared