Why are fish dark on the top side and light on the bottom side? This difference in the colouring is a form of camouflage. If you look down at …
Why do plants look green? The colour of an object is actually the colour of light which it reflects out of the seven colours of white light falling on …
Why can’t flies move about frequently during the night? Like human beings, the flies are also diurnal i.e. they are active during the day and take rest during the …
Why is black ink used in printing? Black ink is used for printing because it generates maximum contrast against a white or light coloured paper. It is also used …
Why are racing cars faster than ordinary cars? Racing cars are so built that they are faster than ordinary cars. They have a stream-lined body to cut the resistance …
Why did the Egyptians mummify the dead bodies? The Egyptians strongly believed in life after death. To help the dead person make the journey from one life to the …
Why is a nurse helping in child birth, called a mid-wife? Mid-wife is a woman who is trained to help deliver babies and offer support and advice to carrying …
Why does a newspaper tear easily in one not in other direction? The newspaper is made up of a compact network of fine fibres of cellulose. The ma-chine used …
