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)

To provide Heat

Explanation:

Gradpoint question

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees.