Which is the most common use for infrared waves?

to determine relative distance

to provide heat

to carry cell phone conversations

to transmit signals

Answer : To provide heat.

Explanation:

Infrared waves are the waves having wavelength 700 nm to 1 mm.

The most common use of infrared waves is "to provide heat" i. e. in heat-sensitive thermal imaging cameras. It is a invisible wave. It can only sensed by a sensation of warmth.

For example:

When an object is hot, It will emit energy in the form of infrared waves.

So, correct option is (b)