ATMOSPHERIC REFRACTION

Two statements are given - one labelled Assertion (A) and the other labelled Reason (R). Read the statements carefully and choose the option that correctly describes statements A and R. Assertion (A): Stars would not twinkle if we viewed them from the moon. Reason (R): Stars appear to twinkle due to atmospheric refraction of starlight.

Refraction Of Light|The Refractive Index|Refraction BY Spherical Lenses

Statement-1 surface wave and sky wave can not be observed on moon. Statement-2: Atmosphere of variable refractive index is require for propagation of surface & sky wave.

Statement-1 surface wave and sky wave can not be observed on moon. Statement-2: Atmosphere of variable refractive index is require for propagation of surface & sky wave.

{:(" Column - I "," Column - II " ),(" a) ""The twinkling of a star"," P) ""Dispersion of light"),(" b) ""Formation of rainbow"," Q) ""Atmospheric refraction "),(" c) ""Ability of the eye lens to adjust its focal length"," R) ""Scattering of light"),(" d) ""Blue colour of sky"," S) ""Accommodation"):}

Assertion : The rainbow is an example of the dispersion of sunlight by the water drops in the atmosphere. Reason : No reflection or refraction of light is involved in the formation of rainbow.

Assertion : The rainbow is an example of the dispersion of sunlight by the water drops in the atmosphere. Reason : No reflection or refraction of light is involved in the formation of rainbow.

The beautiful phenomenon of the rainbow is a combination of different phenomena - dispersion, internal reflection and refrection of light. The rainbow appears in the sky after a rainfall. The water droplets act as small prisms. When sunlight enters the water droplets present in teh atmosphere, they refract and disperse the incident Sunlight. Then, they reflect internally inside the droplet and finally again refract it. As a collective effect of all the phenomena, the seven coloured rainbow is observed. Q. How do refraction and dispersion take place ?

The beautiful phenomenon of the rainbow is a combination of dispersion, internal reflection and refraction of light. The rainbow appears in the sky after a rainfall. The water droplets act as small prisms. When sunlight enters the water droplets present in the atmosphere, they refract and disperse the incident Sunlight. Then, they reflect internally inside the droplet and finally again refract it. As a collective effect of all the phenomena, the seven coloured rainbow is observed. Q. Which three major phenomena are responsible for rainbow ?

The atmosphere of earth extends upto height H and its refractive index varies with depth y from the top as mu = 1 + (y)/(H) . Calculate the apparent thickness of the atmosphere as seen by an observer in space.