Why is the boiling point of a liquid lowered at high altitudes? A liquid boils when the (upward) pressure exerted by its vapours and the (downward) pressure exerted by …
Why does the sky appear red or orange in colour at sun-sets? At sunset, the sunlight has to travel a longer distance through the atmosphere before it reaches us. …
Why can’t Benzene be used as a thermometric liquid even though it is a more sensitive liquid than Mercury? Benzene can expand about six times more than Mercury for …
Why are unmanned spacecrafts sent into space? Many unmanned spacecrafts like Pioneer 10, Voyager 1, Voyager 2 etc. have been sent into space to study the parts of the …
Why are CDs preferred to other forms of recording? Sound information, recorded in CDs through digital coding is very accurate, free of noise and gives excellent sound quality. They …
Why is Charles Babbage known as the ‘Father of Computers’? Charles Babbage (1792-1891) was an English mathematician. He spent most of his life developing the two calculating machines—the Difference …
Why is an enlarged photograph not as clear as the smaller photograph? The clarity of the graphics depends upon the number of pixels per square inch. The more the …
Why is it advised to breathe through the nose than the mouth? The nose has tiny hair called cilia which clean the air off dust particles. At back of …
