Basic Concept of Electricity

INTRODUCTION

Electricity is the modern friend of man.  It has become a part and parcel of our daily life.  Where ever we may cast our eyes, we find the achievements and attainment of electricity.  It has really made the life of a person quite comfortable.

Talking on telephone with friends and relatives, watching football match on T.V. effective & efficient cooling of Air conditioners, cooking the food by cooking range, heating the food by microwave oven, quick ironing of clothes with electric iron etc have been possible only due to our modern friend electricity.

An electric bulb, an electric bell and a room heater, all require electric current for their operation but current produces different effects in each case. Therefore before numerating the various applications of electricity, it is essential that we should consider the various effects of electric current.

WHAT IS ELECTRICITY

The electrons in the outermost orbit are known as valence electrons.  In some elements these valence electrons are loosely bounded to their nucleus and can he dislodged by some means or the other.  Such electrons are also known as free electrons. Certain materials such as Copper, Aluminium have many free electrons.  These free electrons used to move haphazardly in all directions from atom to atom in the material. If, however the free electrons can be caused to move through the material in the same general direction, the net electrons movement is the flow of electricity and is called an electric current.