Question

how refractive index change in atmosphere.explain an example of fire.​

Answer 1

Explanation:

Atmospheric Refraction

What is Atmospheric Refraction?

The atmosphere around earth has layers of air which do not have same temperature. The hotter air is lighter and hence less denser than the cooler air.

Due to the difference in the densities the air layers have different refractive index. When light rays pass through the atmosphere having layers of different refractive index then refraction takes place.

The refraction of light caused by earth's atmosphere is called atmospheric refraction.

Applications of Atmospheric Refraction.

The apparent random wavering or flickering of object seen through a turbulent stream of hot air rising above a fire or a radiator.

Twinkling of stars.

Advanced sunrise and delayed sunset.

Apparent flattening of the sun’s disc at sunrise and sunset.

The stars seems higher than they actually are.

Twinkling of Stars

The twinkling of a star is due to the atmospheric refraction of the star’s light.

While passing through the atmosphere consisting of layers of different refractive index, the light from star undergoes refraction continuously.

Since upper layer (hotter) has a lesser refractive index than the lower one (cooler), starlight bends towards the normal due to which, the star's position appears slightly different from its actual position. Also the physical conditions of the atmosphere keep changing, the apparent position of the star fluctuates which gives rise to the twinkling effect.

Answer 2

Answer:

Refraction increases approximately 1% for every 0.9 kPa increase in pressure, and decreases approximately 1% for every 0.9 kPa decrease in pressure. Similarly, refraction increases approximately 1% for every 3 °C decrease in temperature, and decreases approximately 1% for every 3 °C increase in temperature.

Explanation:

Due to the difference in the densities the air layers have different refractive index.

Example of fire-The soot refractive indices change not only with the position within a given flame but also with the fuel equivalence ratio.