Wednesday, December 19, 2012

DC AND AC CURRENT IN ELECTRIC FIELD

Differences between alternating currents (AC) and direct currents (DC). You can read a brief synopsis of these two electrical systems and then begin your exploration of these inventions by clicking on either AC or DC in the electrical system interactive. By clicking on AC, DC, wire, battery, AC generator, or light bulb you will learn about alternating and direct currents, what exactly an electric current is, and two ways that the currents can be produced.

Alternating Current (AC)

Alternating current (AC) electricity is the type of electricity commonly used in homes and businesses throughout the world. While direct current (DC) electricity flows in one direction through a wire, AC electricity alternates its direction in a back-and-forth motion. The direction alternates between 50 and 60 times per second, depending on the electrical system of the country.

AC electricity is created by an AC electric generator, which determines the frequency. What is special about AC electricity is that the voltage can be readily changed, thus making it more suitable for long-distance transmission than DC electricity. But also, AC can employ capacitors and inductors in electronic circuitry, allowing for a wide range of applications.

Direct Current (DC) Electricity.

Direct current or DC electricity is the continuous movement of electrons from an area of negative (−) charges to an area of positive (+) charges through a conducting material such as a metal wire. Whereas static electricity sparks consist of the sudden movement of electrons from a negative to positive surface, DC electricity is the continuous movement of the electrons through a wire.
A DC circuit is necessary to allow the current or steam of electrons to flow. Such a circuit consists of a source of electrical energy (such as a battery) and a conducting wire running from the positive end of the source to the negative terminal. Electrical devices may be included in the circuit. DC electricity in a circuit consists of voltage, current and resistance. The flow of DC electricity is similar to the flow of water through a hose.

Difference between AC and DC electricity

Electrons have negative (−) electrical charges. Since opposite charges attract, they will move toward an area consisting of positive (+) charges. This movement is made easier in an electrical conductor, such as a metal wire.
Electrons move direct with DC electricity

With DC electricity, connecting a wire from the negative (−) terminal of a battery to the positive (+) terminal will cause the negative charged electrons to rush through the wire toward the positive charged side. The same thing happens with a DC generator, where the motion of coiled wire through a magnetic field pushes electrons out of one terminal and attracts electrons to the other terminal.
Electrons alternate directions in AC electricity

With an AC generator, a slightly different configuration alternates the push and pull of each generator terminal. Thus the electricity in the wire moves in one direction for a short while and then reverses its direction when the generator armature is in a different position.
AC movement of electrons in wire

The charge at the ends of the wire alternates between negative (−) and positive (+). If the charge is negative (−), that pushes the negatively charged electrons away from that terminal. If the charge is positive (+), the electrons are attracted in that direction.

Rate of change

AC electricity alternates back-and-forth in direction 50 or 60 times per second, according to the electrical system in the country. This is called the frequency and is designated as either 50 Hertz (50Hz) or 60 Hertz (60Hz).

Light bulbs in Both AC and DC

Many electrical devices—like light bulbs—only require that the electrons move. They don't care if the electrons flow through the wire or simply move back-and-forth. Thus a light bulb can be used with either AC or DC electricity.