INTRODUCTION

The branch of engineering or science that deals with the static (i.e., stationary) charges is called electrostatics.

When a glass rod is rubbed with a silk cloth, the former attains positive charge and the latter attains negative charge of equal magnitude. Since both the glass rod and the silk cloth are insulators, they retain these charges. These charges are known as static charges and the process comes under the general heading of electrostatics. These charged bodies are considered to be point charges when they are very small as compared to the distance between them. It is the same process due to which huge charges¹ are developed over the clouds. Consequently, a potential difference of millions of volts is developed across the clouds having opposite charges. The static charges can be stored in a device called capacitor. In this chapter, we shall deal with various aspects of electrostatics and electric capacitors.