Question

Dispersion of white light by glass prism and also define spectrum and dispersion.. explain step by step in simple language
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Answer 1

Dispersion of White Light by a Glass Prism :

• The phenomenon of splitting of white light into its constituent colours when it passes through a prism is called dispersion.

• This band of seven colours so obtained the VIBGYOR ( V = violet, B = blue , G = Green , Y = yellow, O = orange , R = red ) is called spectrum.

• Isaac Newton was the first one to use a glass prism to obtain the spectrum of light.

• Light rays of different colours travel with the same speed in vacuum and air but in any other medium their travel with different speeds and bend through different angles which leads to the Dispersion of light.

• Red light has the maximum wavelength and violet light has the minimum wavelength .

• So in any medium, red light travels faster and deviates least while violet light travels slowest and deviates maximum i.e. wavelength varies to velocity varies to 1 upon deviation.