Write source of visible rays and its uses.

Explanation

Visible light is part of radiation emitted by the sun. These rays can be produced by flame, bulb and incendencent lamps also.
This is part of electromagnetic spectrum detected by human eye.
Its frequency varies from `4xx10^(14)` Hz to `7xx10^(14)` Hz. Its wavelength is in range of 700 nm to 400 nm.
Uses :
(i) Human eye (we) is sensitive to radiation of visible rays (waves).
(ii) Due to visible light we can see object around us.
(iii) Different animals are sensitive to different range of wavelength. For example, snake can detect infrared waves.
(iv) For some insect visible range is extended upto ultraviolet range.