• 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.Read More...
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:Read More...
• 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.
WORKING OF AN ELECTRIC BULB
• In a transparent electric bulb, there is a thin filament or a very thin metal wire. The filament heats up when an electric current is passed through it. It heats up so much that it begins to glow and gives out light.
• In case a very large current flows through the bulb the filament gets heated up too much and gets broken, the bulb is said to be fused. Such a bulb cannot give light as the path is not available for current to flow.
Invention of electric bulb:
• The first electric bulb was made in 1809 by Humphry Davy, then It was perfected by Thomas Alva Edison.
• In 1910, William David Coolidge invented a tungsten filament which lasted even longer than the older filaments.
SOURCES OF ELECTRIC CURRENT
• A device that can be used to produce an electric current is called a source of electric current
• Common sources of electric current are cells and batteries (collection of cells) of various shapes and sizes.
• Electricity generated on large scale by Thermal Power Plants and Hydroelectric Power Plants is supplied to our homes and offices.
Thermal power station: