Questions

Color blindness occurs when the cone cells of the retina stop functioning. Give reason.

The deficiency of vitamin A in the body is one of the main causes of night blindness. Justify.

A concave lens diverges the rays of light. Why?

A convex lens converges light rays. Why?

Sunlight is refracted when it is passed through a prism. Give reason.

A diamond appears to shine but a piece of glass cut to the same shape does not shine.

The sun appears on the horizon about two minutes before the actual sunrise.

Stars twinkle. Give reason.

When the letters written on the paper are observed from the top of a glass slab, the letters appear to be slightly raised, why?

When a coin is placed in a glass containing water, it appears to rise a bit. Give reason.