Question

13.
A beam of white light incident on a glass prism gets splitting into
seven colours as VIBGYOR.
Wh
LE
Prism
Cuestions:
al Which colour has a longer wavelength?
b) Write the relation between refractive index and wavelength in
the above activity

Answer 1

Answer:

Red

Explanation:

• a) As the full spectrum of visible light travels through a prism, the wavelengths separate into the colors of the rainbow because each color is a different wavelength. Violet has the shortest wavelength, at around 380 nanometers, and red has the longest wavelength, at around 700 nanometers. b) v is the velocity of light in the medium. Hence refractive index is inversely proportional to wavelength. a and b are constants and λ is the wavelength..

Answer 2

• The red colour light beam has the longest wavelength.

• In the activity mentioned in the question the amount of refraction of the seven coloured beams are separate from each other due to the separate refractive index of these beams.

Now, refractive index = Speed of light in vacuum / Speed of light in given medium.

And,speed of light = frequency × wavelength.

Now,the frequency of the light is always constant.

So,the difference in the numerical values of refractive index is totally dependent on the difference of the wavelengths of different coloured beams.

In this way the wavelength and refractive index are related with each other.