Explain why, when the sun is overhead at noon, it appears white, but when the same sun is near the horizon at sunset, it appears red?

Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.

1. Is she short-sighted or long-sighted?
2. What type of lenses-converging or diverging-would an optician prescribe for her?

Name the atmospheric phenomenon due to which the sun can be seen above the horizon about two minutes before actual sunrise.

Why does the sky appear blue on a clear day?

Why does the sky appear dark (or black) to an astronaut instead of blue?

How many surfaces bound a prism? How many refractions does a beam of white light suffer, when it is passed through a prism?

Why does the sky appear dark instead of blue to an astronaut?

A beam of light consisting of consists of three. namely red (R), Green (G) and yellow (Y) on the prism as shown below. Complete the diagram to show refracted and emergent ray.

Name the defect which is caused when a person’s eye lens hardens.

How is the amount of light entering the eye controlled?