Questions

The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force. The photon has zero rest mass and always moves at the speed of light within a vacuum.

A tone in music is a sound that has definite pitch. Pitch is nothing but the relative highness or lowness of a sound.

IC's (Integrated Circuits) also called as Chips or Microchips whose invention allowed computers to be smaller and smaller.

Deficiency of Iodine cause Goiter also called Enlarged Thyroid. It doesn't give any pain but difficult to swallow and breath are its causes.

Black

Rainfall and addition of fresh water from rivers reduce salinity neat the coasts.

History of Shimla goes back to the period of Anglo –Gurkha war in the year 1808-09. The British connection with the area developed only after this battle between the Sikh rulers of these hills and the Gurkhas from Nepal.