Question

which colour has the highest wavelength and which colour has the least wavelength on visible spectrum

Answer 1

In the visible spectrum- red to violet, red has the highest wavelength[650nm] as well as the lowest frequency.
Violet, being the exact opposite, has the lowest wavelength and highest frequency.
A great simulation that shows this can be found by googling "phet bending light".


I HOPE IT HELPS U.

Answer 2

Answer: Red has highest wavelength and `blue has lowest wavelength.

Explanation:

Electromagnetic wave is defined as the wave which is associated with both electrical and magnetic component associated with them. They can travel in vacuum as well and travel with the speed of light.

The Electromagnetic visible spectrum involves violet, indigo, blue , green, yellow, orange and red which are arranged in order of increasing wavelength and decreasing frequency.  

Thus red has highest wavelength and blue has lowest wavelength.