EVERYDAY SCIENCE

Q. A dark blue suit appears black when viewed in candle light. Why ?

A. Candle light is deficient in blue colour, whereas yellow colour is in excess. When yellow light falls on the blue suit, blue colour is absorbed by it and, therefore, the appearance of the suit is black.

Q. In summer, white or light- coloured clothes are preferred to dark- coloured clothes. Why ?

A. White or light coloured clothes are good reflectors and bad absorbers of heat, whereas dark-coloured clothes are good absorbers of heat. Therefore, in summer, white or light-coloured clothes are preferred, because they absorb very little heat from the Sun’s rays and reflect more. Hence, the person feels more comfortable.

Q. Why is a rainbow seen after rain ?

A. After the rain, some clouds continue to linger in the sky and they contain water droplets. Water droplets act like prisms. The Sun’s rays falling on water droplets suffer dispersion and produce a spectrum. The different colours are viewed in the form of a rainbow.