Question

Huygen's principle of secondary wavelets may be used to

• A. find the velocity of light in vacuum
• B. explain the practical behaviour of light
• C. find the new position of a wave front
• D. explain Snell's law

Answer 1

Answer: (C), (D)

The correct options are
C find the new position of a wave front
D explain Snell's law

Huygen's principle states that every point on a wave-front may be considered a source of secondary spherical wavelets which spread out in the forward direction at the speed of light. The new wave-front is the tangential surface to all of these secondary wavelets.

Hence option C is correct.

Also this can be used to find the expression of snells's law ${\mu }_{1}sini={\mu }_{2}sinr$

Hence option D is correct.