| |
|
|
| |
 |
| Introduction |
|
| Appliances used in our day to day life are based on the principles of electricity and magnetism. Electricity is one of the most important sources of energy. Lights, fans, motors, radios and television are some common appliances which work on electricity. |
| |
 |
| |
| Benjamin Franklin |
| |
| Historically, it was frictional electricity that was understood first. About 2000 years ago, a Greek philosopher named Thales observed that, a piece of amber rubbed against another material, attracted small objects. The word 'electricity' is derived from the Greek word "electron" meaning amber. The ancient Greeks, however, did not proceed beyond this finding. In 1600 A.D, Dr. Gilbert, a physician showed that besides amber, other substances such as glass and diamond also possessed the same property. But it was the American inventor, Benjamin Franklin (1706 - 1796) who experimented with electricity and made major inroads in understanding the phenomenon. |
| |
 |
| |
| Alessandro Volta |
| |
| By the middle of the eighteenth century, there were machines that could generate large electrical charges. Static electricity may produce dramatic effects but it is of very little practical use to us. It is the current electricity that provides us with all our requirements from basic lighting to super computers. The invention of a device for producing current electricity was the result of an accidental discovery by the Italian professor Luigi Galvani. But it was Alessandro Volta who made the first battery in 1800. Today we understand the use of these batteries, which produce chemical, electrical and magnetic effects. |
| |
|
|
| |
|
|
| |
|
|
|
