ELECTRICITY

ELECTRICITY

Electricity
Electricity is a set of physical processes associated with the presence and flow of electric charge. Electricity gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and the flow of electrical current. In addition, electricity permits the creation and reception of electromagnetic radiation such as radio waves. In electricity, charges produce electromagnetic fields which act on other charges. Electricity occurs due to several types of physics:

• Electric charge: is a property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter produces electromagnetic fields.

• Electric current: a movement or flow of electrically charged particles, typically measured in amperes.

• Electric field: This is a simple type of electromagnetic field which is produced by an electric charge even when there is no electric current. The electric field also produces a force on other charges that are within its own area of jurisdiction. Moving charges additionally produce a magnetic field.

• Electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.

• Electromagnets: electrical currents generate magnetic fields, and changing magnetic fields generate electrical currents

Uses of Electricity
The use of electricity gives a very convenient way to transfer energy, and because of this it has been adapted to a huge, and growing, number of uses. The invention of a practical incandescent light bulb in the 1870s led to lighting becoming one of the first publicly available applications of electrical power. Although electrification came along with its own dangers, replacing the naked flames of gas lighting greatly reduced fire hazards within homes and factories. Public utilities were set up in many cities to target the growing market for electrical lighting.

Through electricity, the light bulb although an early application of electricity, operates by Joule heating i.e the passage of current through resistance and thereby generating the required heat and light energy for the bulb to function.

The Joule heating effect employed in the light bulb also sees more direct use in electric heating. While this is versatile and controllable, it can be seen as wasteful, since most electrical generation has already required the production of heat at a power station. A number of countries, such as Denmark, have issued legislation restricting or banning the use of electric heating in new buildings. Electricity is however a highly practical energy source for refrigeration, with air conditioning representing a growing sector for electricity demand, the effects of which electricity utilities are increasingly obliged to accommodate.

Electricity is a necessity in all telecommunications companies. The electrical telegraph which was produced in 1837 by Cooke and Wheatstone was one of its earliest applications. With the construction of intercontinental and transatlantic telegraph systems in the 1860s, electricity had advanced communications in minutes across the globe. Although optical fibre and satellite communication technology have taken a share of the market for communications systems, electricity is still expected to remain an essential part of the process.

The effects of electromagnetism are most visibly employed in the electric motor, which provides a clean and efficient means of motive power. A stationary motor such as a winch is easily provided with a supply of power, but a motor that moves with its application, such as an electric vehicle, is obliged to either carry along a power source such as a battery, or to collect current from a sliding contact such as a pantograph, placing restrictions on its range or performance.

Electronic devices make use of the transistor, perhaps one of the most important inventions of the twentieth century, and a fundamental building block of all modern circuitry. A modern integrated circuit may contain several billion miniaturized transistors in a region only a few centimetres square.

Electricity is also used to fuel public transportation, including electric buses and trains.