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

Step 1: Recall what a mirage is.
A mirage is an optical illusion, commonly seen as a false pool of water on a hot road, caused by the bending of light near the ground.
Step 2: Identify the cause of bending.
Near a hot surface, the air layer touching the ground becomes much hotter, and hence less dense, than the air layers above it. This creates unequal heating of different parts of the atmosphere, so each layer has a slightly different refractive index.
Step 3: Explain the light path.
Light coming from the sky bends gradually as it passes through these layers of changing density and undergoes total internal reflection near the hot layer close to the ground, then travels up to the eye. This bent ray looks like a reflection from a water surface.
Step 4: Rule out other options.
Equal heating would keep the air density uniform and no bending would occur. Magnetic disturbances do not affect the path of visible light. Ozone depletion changes how much ultraviolet light is absorbed, it does not create the temperature gradient needed for a mirage.
Final Answer: D) Unequal heating of different parts of the atmosphere.