- It is produced by hot bodies i.e. vibrations of atoms and molecules. (Hence also called heat waves).
- It is not detected by human eye but snake can detect it.
- These waves are readily adsorbed by water, CO2, NH3 etc.
- Its frequency range is 10^11 Hz to 10^14 Hz.
- Its wavelength lies between 1mm - 700nm.
- It is detected by thermopiles, bolometer, infrared photographic film.
Uses:
- Infrared lamp is used in physical therapy i.e. to treat muscular strain.
- It is responsible for keeping average temperature through green-house effect.
- Infrared detectors are used in earth satellite, both for military purposes and to observe growth of crops.
- To provide electrical energy to satellite by using solar cells.
- To take photographs during fog and smoke.
- It is used to study molecular structure by taking infrared absorption spectrum.
