Every colour travels with the same speed in a transparent medium.

Why is the colour of the sky blue?

Draw a neat diagram to show the refraction of a light ray through a glass prism,and label on it the angle of incidence,and angle of deviation.

Which of the following phenomena is $NOT$ involved in the formation of a rainbow?

Account for the following:
$(a)$ Part of the human eye that helps in changing the focal length of the eye lens.
$(b)$ The condition resulting due to the eye lens becoming cloudy.
$(c)$ The factors on which the colour of the scattered white light depends.
$(d)$ The range of vision of a normal eye.
$(e)$ The sky appears dark to the astronauts in space.

How can we explain the reddish appearance of the Sun at sunrise or sunset? Why does it not appear red at noon?