Q.Why is the Earth spherical and not any other shape?
A.The answer lies in the gravitational force,which pulls every object towards each other. The Earth is thought to have formed from a huge, rotating cloud of gas. In the newly born Earth, gravity pulled parts at the same distance from the centre with the same [...]
Three primary colours (red, green and blue) produce colour television pictures. These combine to create a whitish light with a colour temperature close to that of daylight (5,500 to 6,500 Kelvin).
Colour temperature is a way of describing the relative amounts of the different colours that make up light from a particular source. It is the [...]