Question

We observe twinkling of stars due to
1) constant change of refractive index of the medium between the stars and the Earth because of temperature variation
2) frequent and periodic fluctuation of temperature of the surface
3) great distance of stars from the Earth
4) rise and fall of gaseous ball of fire inside the stars

Answer 1

1) constant change of refractive index of the medium between the stars and the earth because of temperature variations