Question

Mirage is due to:

• A. Equal heating of different parts of the atmosphere
• B. Magnetic disturbances in the atmosphere
• C. Depletion of the ozone layer in the atmosphere
• D. Unequal heating of different parts of the atmosphere

Hint:

Think about why the ground looks shiny like water on a hot road, it involves bending of light through air of different temperature.

Answer 1

The Correct Option is D

A mirage is the false appearance of water seen on a hot road or in a desert, and it is explained using refraction of light through air of varying temperature.

1. Equal heating of the atmosphere is ruled out because if every layer of air were at the same temperature, the density and refractive index would stay the same everywhere and light would travel in a straight line with no bending.
2. Magnetic disturbances do not bend visible light at all, light bending is controlled by the medium's refractive index, not by magnetic fields.
3. Depletion of the ozone layer changes ultraviolet absorption high in the atmosphere, it has no connection to the temperature gradient near the ground that produces a mirage.
4. Unequal heating of different parts of the atmosphere makes the air near a hot surface less dense than the air above it. Light from the sky curves through this changing density and reflects internally near the ground, reaching the observer's eye as if coming from a water surface.

So option D is the correct cause of a mirage.