Electricity basics

The concept of electricity is probably a magic or a dream for a 100 years ago man to think. But today electricity is everywhere around us It lights up our homes, cooks food or us, show international gossip on our televisions, gives us light in dark. In short life is impossible without electricity. 90% of today's technology is based on electricity. It made our lives so easy and comfortable. But little of us know that how 



electricity is generated and from where it comes.

If we talk in scientific language, electricity is simply a form of energy which results from flow of electrons. All matter is made up of atoms and a atom contains specific number of electrons, protons and neutrons.  Atom may gain or lose an electron due to outside forces. The free movement of these electrons constitutes an electric current.

The fundamentals of electricity were discovered by British scientist Michael Faraday during the 1820s. He gave an basic principle: electricity is generated by the movement of a rotating shaft or a disk of magnet between between the poles of magnet. Due to electrical and magnetic forces the rotational shaft generates an electromotive force (EMF). With the help of this emf electricity is generated. Even today's electricity system is based on same principle

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TYPES OF ELECTRIC CURRENT

Electric current is o two types:

1) Alternating Current (AC)
2) Direct Current (DC)

  ALTERNATING CURRENT

AC is the variable form of electricity. In AC current is swing between two values (highest value and lowest value) and changes its direction alternately. This is the AC current which is supplied to our homes and used in all over the world. This is generated by an AC electric generator. AC is very much cheaper then DC batteries that's why it is used so commonly

  DIRECT CURRENT

Direct current is the unidirectional current. It is the static form of energy. Cells, Batteries are some example of DC current. DC current is very much expensive for domestic use or use at large scale. So its use is limited.

We can obtain a DC current from AC current. For this we have some special circuits. In India the AC is supplied at 240 volts. So These circuits have a Transformer for stepping down AC then some diodes and ICs for rectifier circuit.

METHODS OF GENRATING ELECTRICITY

There are broadly three method from which electricity is generated

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  SOLAR ENERGY

The solar energy from sun is transferred to electrical energy to produce electricity by using some special devices. These devises are called solar panels. solar panels are constructed from a semi-conductive material which contain some electrons. When photons from sun hit a solar cell the electrons absorbs this energy and it transforms the electrons in to conduction electrons. If the energy of these photons is great enough then the electrons are able to become free and carry an electric charge through a circuit and electricity is generated

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  WIND ENERGY

Wind power generates energy by converting wind energy in to electrical energy. The device use for that called wind mile. 1000s of windmills are plants in big empty grounds. The wind will be gushed through the wings which makes the wings to rotate and which in turn will generate electricity. The wind should be abundantly available where these windmills are planted.

The copper shaft is rotated by the rotation of wings of windmills which generates emf and electricity is produced.

TURBINES

Turbines are connected to three propeller-like blades that connect to a rotor. Generally steam is used to rotate the blades of turbine. This steam can be generated by biogas, nuclear energy e.t.c. The rotor connects to the main shaft, which turns inside the generator housing. Here, a magnetic rotor causes loops of cooper wire to rotate. This causes electrons inside the cooper to flow; creating electrical energy.

In India electricity sector had an installed capacity of 223.343 GW as of March 2013. We have fifth position in world for generating electricity. Non Renewable Power Plants constitute 87.55% of the installed capacity and 12.45% is constitute by Renewable sources.

sources: http://www.articlesbase.com/electronics-articles/electricity-basics-6570885.html