Question

Assertion: The clouds in the sky generally appear to be white in colour.

Reason: Diffraction due to clouds is efficient in equal measure at all wavelengths.

A. Both assertion and reason are true and the reason correctly explains the assertion.
B. Both assertion and reason are true but the reason doesn’t explain the assertion correctly.
C. Assertion is true but reason is false.
D. Assertion is false but reason is true.
E. Both the assertion and the reason are false.

Answer 1

Clouds appear white because of Mie scattering which scatters all colors of sunlight equally; this is not caused by diffraction. Rainbows, on the other hand, showcase dispersion of light, where different wavelengths are refracted by different amounts within raindrops, creating a spectrum of colors.

Step-by-step explanation:

The assertion that clouds in the sky generally appear to be white is true; however, the reason provided is false. The clouds appear white because they scatter all wavelengths of light from the sun roughly equally due to Mie scattering, which is more dependent on the sizes of the cloud particles relative to the wavelength of light, not diffraction. The process of dispersion is what separates white light into the spectrum of colors in a rainbow, not the general appearance of clouds.

When light encounters raindrops, it gets refracted, reflected inside the drop, and then refracted again when it leaves. Different wavelengths of light are refracted by different amounts, which separates the light into a spectrum of colors. This is why we see rainbows having red on the outer edge and violet on the inner edge. However, this dispersion is not the reason clouds appear white, which is why the reason does not correctly explain the assertion.