Assertion: At the first glance, the top surface of the Morpho butterfly's wing appears a beautiful blue-green. If the wind moves the colour changes.
Reason: Different pigments in the wing reflect light at different angles.

Options

A. (a) If both the assertion and reason are true and reason explains the assertion assertion.
B. (b) If both assertion and reason are true but reason does not explain the assertion
C. (c) If assertion is true but reason is false.
D. (d) If assertion is false but reason is true.

Answer

C

Explanation

The Morpho butterflies are among the largest in the world, with a wingspan of `7.5` to `20cm`. The males have the beautiful metallic blue upper wings. Their iridescence is due to the microscopic structure of their wings. In these butterflies iridescence is caused by multiple slit interference. Sunlight contains a full range of light wavelengths. Interference occurs when light hitting the wing combines with light reflected off the wing. Light is a wave. If the crests and throughs of waves are aligned or "in phase" they will cause constrictive interference and iridescence.