Question

Out of the following, select the correct statements: This question has multiple correct options
(A) Mirage and looming take place in hot places
(B) An object is not visible when its refractive index is unity
(C) On increasing the angle of incident, the angles of deviation also increase
(D) During hot summer days. The trees and other tail objects seem to be Quivering because the density of air changes in and irregular way

Answer 1

Hint Here, we know that It is greater than at height according to the density and refractive index of air near the ground. And also, we know the reverse effect of mirage can occur in cold regions including glaciers and frozen lakes and seas. We evaluate every statement here and find the right one.

Useful Concept
When the light rays from the sun pass straight into the atmosphere, these light rays travel through the hot and cold air at varying speeds.

Complete step by step solution
Given by,
We analyses the correct statement
Looming is a kind of mirage seen over cooler air where warm air lies. The mirage is caused by the absolute inner reflection of light in air layers of varying densities. In a desert, during the daytime, the sand is very hot and the air layer in contact with it becomes heated and lighter. The lighter air rises and the denser air descends from the top.
When the refractive index of the body is equal to one then it does not reflect any light wave and it cannot be seen.
The deviation angle first decreases with increasing incidence angle, and then it increases.
In summer due to heating air the hot air rises and cold air comes down due to which the refractive index of each layer changes every time, that's why objects seem to be quivering.
Hence,
Mirages and looming take place when the density of air changes. An object is not visible when its refractive index is unity.
On increasing the angle of incidence, the angle of deviation also increases. During hot summer days, the trees and other all objects seem to be quivering because the density of air changes in an irregular way.

Thus, the above A, B, C, and D option is correct to one relate others.

Note when a hot place, air at a height above the ground is cooler than air. There is less concentrated hot air. Therefore, with height, the refractive index of air rises in still air. As a consequence, light from large objects such as a tree passes through a medium whose refractive index decreases towards the earth.