Questions

In all the above given options, there is no chemical change or reactions takes place only the shape or physical state is changed.

The disease that has been eradicated from the world is small pox. Smallpox was an infectious disease caused by one of two virus variants, Variola major and Variola minor. The last naturally occurring case was diagnosed in October 1977 and the World Health Organization (WHO) certified the global eradication of the disease in 1980.

A floppy disk contains both circular tracks and sectors in it.

Glass is made from heating of sand. To melt sand to make glass, the temperature needed is above 1800 deg celcius.

A rainbow is a natural spectrum appearing in the sky after a rain shower. It is caused by dispersion of sunlight by tiny water droplets, present in the atmosphere. A rainbow is always formed in a direction opposite to that of the Sun. The water droplets act like small prisms. They refract and disperse the incident sunlight, then reflect it internally, and finally refract it again when it comes out of the raindrops.