Ultraviolet rays(UV rays)
It covers wavelengths ranging from about 4 × 10–7 m (400 nm) down to 6 × 10–10m (0.6 nm).
- The UVrays are produced by special lamps and very hot bodies (sun).
- UV rays have harmful effects on humans.
- UV lamps are used to kill germs in water purifiers.
- For example:-
- When UV rays fall on the skin of humans then it leads to the production of a pigment called melamine which causes tanning of the skin.
- In order to protect from UV rays glasses are used,as they get absorbed by the glasses.
- UV rays help in LASER assisted eye surgery.
- As UV rays have very short wavelength so they can be focussed into narrow beam of light.
- The ozone layerwhich is present outside the atmosphere protects us from the harmful UV rays.
- Ozone has a property of reflecting the harmful UV rays.
- But due to the use of CFC (chlorofluorocarbon) ozone layer is depleting.
- So if ozone layer gets depleted humans will get exposed to harmful UV rays coming from the sun.