Question

1.4 If a beam of red light and a beam of violet light are incident at the
same angle on the inclined surface of a prism from air medium and
produce angles of refraction r and v respectively, which of the
following is correct?
(a) r=v; (b) ; (c)=r>v; (d)r<v;​

Answer 1

Answer:

(d) r<v

Explanation:

As red has highest wavelength, it will disperse with very less angle whereas violet, who has the lowest wavelength, will disperse with an angle greater than red one.

HOPE YOU UNDERSTAND

Answer 2

(d) r<v is the correct answer.

What happens when light ray is passed through prism?

• When a ray of light travelling in air medium is incident on an inclined surface of a prism, it gets dispersed in seven visible wavelengths of light.
• The light ray undergoes refraction and the angle of refraction for all the different wavelengths is different.
• Depending on the wavelength of light, angle of refraction varies.
• Large wavelength is refracted less, which means longer wavelengths have less angle of refraction.
• Small wavelength is refracted more which means smaller wavelengths have more angle of refraction.

Therefore, violet light having small wavelength has more angle of refraction as compared to red light which is larger in wavelength.