Short Question Answers

Q1. Explain the formation of a mirage

Ans.

1. Mirages are formed due to total internal reflection of light.
2. On hot summer days the air near the ground becomes hotter. Hence it becomes less dense.
3. Light ray from a tall object passes through air with decreasing refractive index towards ground.
4. So, the angle of incidence near the ground exceeds critical angle, as a result total internal reflection takes place.
5. For a distant observer light appears to come from somewhere below ground. So the observer assumes that the light reflected from the ground like by a pool of water.
6. This forms an inverted image of tall object and causes optical illusions to the observers. This phenomenon is known as “mirage”.

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