Science : Ch 11 – The Human Eye and the Colourful World

The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:

The bluish colour of water in deep sea is due to:

In an experiment to trace the path of a ray of light through a triangular glass prism, a student would observe that the emergent ray

Power of a lens is the measure of the degree of

Ankit remarked that he has seen wavering of objects when seen through a stream of hot air rising above a tandoor or a fire. He said that the air just above the fire becomes hotter than the air further higher up. He further said that this wavering can also be seen in the earth’s atmosphere as the earth’s atmosphere is not evenly distributed and several observations can be explained on the basis of this phenomenon,name the phenomeoneon

Arjun remarked that he has seen wavering of objects when seen through a stream of hot air rising above a tandoor or a fire. He said that the air just above the fire becomes hotter than the air further higher up. He further said that this wavering can also be seen in the earth’s atmosphere as the earth’s atmosphere is not evenly distributed ,Name two observations which can be explained by the above phenomenon.

Why don’t planets twinkle?

What would have been the colour of sky if the earth had no atmosphere

Power of a lens is

Lenses which have both concave and convex structure.

When a person can see faraway objects but not nearby objects.

Myopia can be corrected by using

A concave lens of short focal length has greater

The sky appears black to an astronaut as there is no

The refractive index of glass is least for