Introduction

Have you ever observed the nature and the various spectacular events like formation of rainbow on any rainy day?

Whenever we observe nature keenly, we can easily understand that the various events in nature like blowing of wind, flow of water, motion of planets, formation of rainbow, different forms of energies, the function of human bodies, animals, etc. are happening or taking place according to some basic laws. The systematic study of these laws of nature governing the observed events is called science. For our convenience, clear understanding and systematic study of Science is classified into various branches. Among these branches Chemistry, Mathematics, Physics, Botany, Zoology, etc. are ancient branches and Bio−technology, Bio−chemistry, Bio−Physics, Computer science, Space Science, Genetic engineering, nano technology etc. are considered to be modern branches of science and engineering. One of such ancient and reputed branches of this science is Physics.