Electricity and Circuit Notes

INTRODUCTION

•    Electricity is a basic part of nature and it is one of our most widely used forms of energy.

•    Electricity play an important role in our day to day life.

•    We are dependent on many electrical and electronic appliances to do our daily chores smoothly.

For e.g. Television, Refrigerator, Fan, tube-light and many more.

•   Before electricity generation began slightly over 100 years ago, houses were lit with kerosene lamps, food was cooled in iceboxes, and rooms were warmed by wood-burning or coal-burning stoves.

Definition of electricity:

•   Electricity is a form of energy. In other words electricity is the flow of electrons.

SOURCES OF ENERGY

•    Coal, natural gas, oil, nuclear power and other natural sources, are called primary sources of energy and electricity is the secondary energy source, that is obtained from the conversion of other sources of energy.

•    Thunder and lightning are due to naturally generated electricity.

•    In a lightening stroke, a very large amount of charge flows through the air, heating it up to produce the bright light. Air expands rapidly on heating producing a large sound.

Discovery of the fact that lightening is electricity by Benjamin Franklin:

ELECTRIC CURRENT

•    Most of the electric and electronic appliances that we use in our day to day life work when an electric current flows through them.

•    An electric current is a flow of electric charge through an electrical conductor.

•    Electric current flows when there is voltage present across a conductor.

      e.g. electric bulb.