Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?

Which of the following statements is correct regarding the propagation of light of different colours of white light in air?

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 colors, the red light

The bluish colour of water in deep sea is due to

When light rays enter the eye, most of the refraction occurs at the