Induction:
When a wire passes through a changing magnetic field, it develops a current through it. This process of generating current is called an Induction. A British scientist, Michael Faraday, discovered this process. Electromagnetic induction is very important for the generation and transmission of electricity over long distances. The unit of magnetic induction is tesla (T).
Muhammad Ali
Reference:
http://library.thinkquest.org/13526/c3c.htm
http://ieee-virtual-museum.org/collection/tech.php?taid=&id=2345820&lid=1

Electromagnetism:
Magnetism is a force that attracts and repels. A magnet is anything that is magnetized and has a magnetic force. The magnetic force forms a magnetic magnetic field which has some line of force and which can attract or repels poles. James Clerk Maxwell figured out that there is an electromagnetic field and that light is also dependent on that. There are many devices and technologies which solely depends on Electromagnetism. Muhammad Ali Reference:
http://ieee-virtual-museum.org/collection/tech.php?taid=&id=2345820&lid=1

Ohm's Law:
Ohm's Law states that the current passing through an electrical circuit is directly proportional to voltage and inversely proportional to the resistance. In an algebraic form, it can be written as:
V= IR , where V represents the Voltage (Volts) , I represents the current (Ampere), and R represents the resistance (Ohms).
This law was discovered by George Ohm. This law is still used by engineers and electricians to measure the voltage of an electrical circuit.
Muhammad Ali
Reference:
http://en.wikipedia.org/wiki/Ohm%27s_Law

Parallel Circuits:
There are two types of electrical circuits. Series Circuit and Parallel Circuit. In Series curcuit, the current flows through a single path. On the other hand, the current flows through the multiple path in parallel circuit. Parallel circuit consists of more resistors. It will not stop the flow of current only because of a damaged path in a circuit. They are used in everyday wiring and are more useful than series circuit.

Muhammad Ali
Reference:
http://regentsprep.org/Regents/physics/phys03/bparcir/default.htm

Alternating Current
As a definition, an alternating current is an electrical current whose electrons, magnitude, polarity, and direction are constantly alternating. The wave form taken by an AC current, or that best represents it is a sine wave, just like the one almost everyone takes in high school math. Moreover, it refers to the type of electricity our homes receive. If we look back at the early stages of AC current we find that the creator of this concept was an American physicist called William Stanley Jr. that started of with simple ideas such as the induction coil that later on became the modernized AC current used nowadays, this also was of course thanks to the contributions of many, of whom we cannot but to mention Nicolas Tesla and George Westinghouse. If some of you are wondering why AC over DC, the question is really simple. AC power could be sent over many miles, a feature that wasn’t present in DC. In addition, alternating currents could be stepped up to a very high voltage, thus reducing the power lost to a minimum amount.
Camil Boulos
Refernce: http://www.teslasociety.com/ac.htm
http://en.wikipedia.org/wiki/Alternating_current

Direct Current
In a direct current, and unlike the alternating one, we have a constant flow of electric charges. In other words, the electric charges flow in the same direction. DC current had also another name known as the Galvanic current. Such a current consists of a source of electrical energy and a conducting wire for the flow of electrons, which some refer to it (the flow of electrons) as being similar to the flow of water through a hose. At the beginning of electrification (before AC was developed), direct current was a “king”, it started to become common to the public who began to accept it as the optimal way for a modern life. On another note, Thomas Edison, the founder of this concept became a recognized figure in society, gaining the love and respect of his environment thanks to his contributions for a better life.
Camil Boulos
Refernece: http://www.school-for-champions.com/science/ac.htm
http://en.wikipedia.org/wiki/Direct_current
http://www.pbs.org/wgbh/amex/edison/sfeature/acdc.html


Polyphase AC
After discussing the nature and history of the alternating current above, it is important to note that AC can be categorized under three different systems; single-phase, two-phase, and three-phase alternating current. The last two are also known as polyphase AC. If some of you are wondering what a polyphase AC is, it is an electric system that have two or more (poly) energized electrical conductors carrying the AC currents in which stable intervals of time separate between each one (refer to figure). Finally , it is essential to note that this type of system is the most commonly
used type nowadays


Camil Boulos
Reference: http://en.wikipedia.org/wiki/Polyphase_system
Empires of Light page 154


Kirchoff's Laws
Kirchoff's Laws, are a set of rules established by Gustav Kirchoff, a German physicist who is considerably one of the major contributors of “electricity”. His laws basically deal with the conservation of energy and charges in circuits. More specifically, he said that at any point on the circuit, the flow of electric charges going out from this particular point is equal to that flowing towards it. Second, he also came up with the theory ∑∆V=0, in other words the voltage sum in a closed circuit is always equal to zero.
Camil Boulos
Reference: http://www.pa.msu.edu/courses/1997spring/PHY232/lectures/kirchoff/kirchoff.html
http://en.wikipedia.org/wiki/Kirchhoff's_circuit_laws


Current The definition of an electric current is, a flow of microscopic particles called electrons flowing through wires and electronic components. An electric current can be measured by looking at the rate at which a charge passes by a point on a circuit. Current is measured in amperes, also known as amps, and can be found by dividing the amount of charge over the amount of time passed.
Brad Ham
Reference: gbs.glenbrook.k12.il.us/Academics/gbssci/phys/Class/circuits/u9l2c.html
en.wikipedia.org/wiki/Electric_current


Resistance Electrical resistance is very much associated with electric current, talked about above. Resistance is the amount at which an object resists the electrical current flowing through it. The unit by which resistance is measured is ohms. An easy analogy to use is of water flowing through pipes. The resistance is created by the friction between the water and the pipe as well as any objects that may be in the path of the flow, affecting the rate at which the water moves. The same occurs with an electrical charge in a circuit. For the most part there are three factors which affect resistance. First, the total length of the wires, second, the cross-sectional area of the wires, and third, the material from which the wire is made.
Brad Ham
Reference: www.glenbrook.k12.il.us/gbssci/phys/class/circuits/u9l3b.html
en.wikipedia.org/wiki/Electrical_resistance
hyperphysics.phy-astr.gsu.edu/hbase/electric/resis.html


Voltage By definition, voltage is the difference of electric potential between two points of an electrical or electronic circuit, and is expressed in volts, or in other words joules per coulomb. It was named for Alessandro Volta for his groundbreaking work with electrical charges and electric potential. (Voltage can also be referred to as electric potential) A more simple way of describing how voltage is measured is by comparing it to length and distance, because it is a measurement between two things.
Brad Ham
Reference: amasci.com/miscon/voltage.html
en.wikipedia.org/wiki/Voltage


Power Electrical power is defined as the amount of work done by an electric current. How power works is, when an electric current flows in a circuit with resistance, it does works. Depending on what device is being used, the work is converted into a useable form such as heat, light, motion, or sound. Another way in which power can be describe, also a more mathematical one, is the rate at which energy is converted from the electrical energy of the moving charges to some other form. The unit by which power is measured is the watt, which is named for James Watt whose most notable achievement is his critical improvements to the steam engine.
Brad Ham
Reference: en.wikipedia.org/wiki/Electric_power
hyperphysics.phy-astr.gsu.edu/hbase/electric/elepow.html