Question

what is atmospheric refraction explain with the help of a labelled diagram that the position of a star is seen as by is not it's true position​

Answer 1

rarer to denser bends towards normal

$and \:$

if denser to rarer bends away from normal

$hope \: it \: helps \: u \:$

Answer 2

Atmospheric refraction can be defined as the phenomenon in which light deviates from its straight line path due to refraction at various air density levels as the height varies.

The position of the star seen by us is not its true position because of the phenomenon mentioned above. The light coming from the star gets refracted in between its long journey to the earth.  As shown in the picture attached, the actual position of the star is below the position seen by us.