Question

Assertion : A secondary rainbow have inverted colours than the primary rainbow.
Reason : The secondary rainbow is formed by single total internal reflection.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (C)

In the formation of secondary rainbow, light suffers two total internal reflections instead of one. In this, ray undergoes two internal partial reflections having a maximum deviation of about 50º for red and 54º for violet. Also secondary rainbow will sometimes be formed with inverted colours. Secondary rainbow is fainter than the primary for two reason (i) the light has undergone two internal reflections and has thereby becomes weakened, (ii) there is greater angular dispersion in this rainbow than in the primary