Physics
Stars twinkle because

the distance of the stars from the earth changes with time.
the intensity of light emitted by them changes with time.
None of these
the refractive index of the different layers of the earth's atmosphere ch

ANSWER DOWNLOAD EXAMIANS APP

Physics
Rainbows are produced when sunlight :

Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction and internal reflection.
None of the given statements is correct.
Incident on raindrops hanging in the atmosphere is dispresed after suffering reflection.
Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction

ANSWER DOWNLOAD EXAMIANS APP