Write source of infrared waves. Also write their uses.

Explanation

Infrared waves are produced by hot bodies and their molecules. Infrared waves lies between microwave and visible region of electromagnetic spectrum.
LED also produce infrared waves.
These rays are also known as heart waves.
Reason behind these rays being called heat waves is such that these rays absorb water molecules in matter present `(CO_(2), NH_(3))`.
By absorbing these waves kinetic energy of molecules increases hence they et heated. They impart energy of neighbouring molecules hence these molecules get heated hence they are called heat waves.
Uses :
(i) Infrared bulb are used in physical therapy.
(ii) Due to green house effect average temperature of the earth is maintained.
(iii) Infrared sensors are used in military purpose and growth of crop in agriculture.
(iv) LED is used in remote control of TV, video recorder and Hi - Fi system.