Electricity

Most of the electrical charge is carried by the electrons and protons within an atom. The electrons are said to carry a negative charge, while the protons carry a positive charge. Protons and electrons attract each other, the archetype of the "opposites attract" cliché. In contrast, two protons repel each other, just like two electrons. Protons and electrons create electric fields, which exert a force called the Coulomb force, which radiates outward in all directions. 

Because protons are generally confined to the nuclei embedded within atoms, they are not as free to move as electrons. Therefore, when we speak of electric charge, we almost always refer to a surplus or deficit of electrons. When there is an imbalance of charges, and the electrons are able to flow, an electric current is created. 

The unit for measuring electrical charge is the coulomb (C), named after Charles-Augustin Coulomb, an 18th century French physicist. Coulomb developed the law that says "as charges are repelled, charges are attracted. A coulomb is defined as the amount of charge carried by a current of one ampere for one second. Electrical engineers often prefer to use a larger unit for the charge, the ampere-hour, which equals 3600 C. 

As defined by the dictionary, the voltage between two points of an electric circuit or electric field is equal to the work that the electric field does in transferring a positive unit charge from one point to the other. In a conservative electric field, the work does not depend on the displacement path of the load; in this case the voltage between the two points coincides with the difference in potential between the points.

Voltage can be calculated using two different definitions. (I) One uses charge and states as follows:

"the voltage difference between two points or terminals is the work required in joules to move a charge coulomb from A to B. "

The formula to calculate it is the following:

The second way to calculate voltage is using Ohm's law. This takes into account different variables within a circuit. 

The formula is the following:

Where V is voltage in volts; I is current in amps; and R is resistance in ohms

Electric current is the flow of electrons through a complete circuit of conductors. It is used to power everything from our lights to our trains. This means that, in a circuit, the current is the movement of electrons through a wire. Electric current is measured in amps (amps) and refers to the number of charges moving through the wire per second. For a current to flow, the circuit must be closed; in other words, there must be an uninterrupted path from the power source, through the circuit, and then back to the power source.

If the circuit were to be a stream, the current would be the rate at which the water flows. 

The current of a circuit can be calculated through various ways, the most common of which is using Ohm's law with the following formula:

It can also be calculated with different variables such as coulombs:

Resistance is an electrical quantity that measures how the device or material reduces the flow of electrical current through it.

Resistance is measured in units of ohms (Ω).

If we make an analogy with the flow of water in pipes, the resistance is higher when the pipe is thinner, so the flow of water is reduced.

Resistance can be calculated in varios ways. The most common one is through the use of Ohm's law, which states that resistance is equal to voltage over current:

The resistance of a material can also be calculated using the measurements of the actual material. The formula is the following:

Whether energy is used in a mechanical or electrical environment, the definition of energy remains the same. The way it can be discussed may be slightly different, but nevertheless the definition and actuality of it is exactly the same.

Electrical power is the rate, per unit of time, at which electrical energy is transferred by an electrical circuit. It is the rate of doing the work. In terms of an electrical circuit, electrical energy is the rate, per unit of time, at which electrical energy is transferred by an electrical circuit.

The unit of power is the Watt indicated by the symbol W and named after the Scottish engineer James Watt (1736-1819). A watt is the speed at which a current of one ampere flows through a network that has an electrical potential difference of one volt.

There are several formulas to calculate power. These are as follows:

Where W is power in Watts, V is voltage in Volts, R is resistance in Ohms, and I is current is amps.

In the field of technology, energy is a fundamental part, since all devices and systems require an energy attribute for their operation. It is well known that energy is the ability to do work. Thus, Electrical energy is the ability of an electrical circuit to produce work by creating an action.

This energy is generated by the movement of electrons through a medium, usually a wire, and it is used for an almost infinite amount of things. From turning the lights on to allowing a Tesla to move around. 

Just like any type of energy, electrical energy is measures in Joules (or kWh).

The formula is the following:

E is energy; V is volage; I is current; and t is time in seconds.

Ohm's law was discovered by George Ohm in 1781  and it establishes the relationship between voltage, current and resistance. Given the relationship between these three elements, once two of them are known, it is possible to calculate the third one.

Ohm's Law states that Voltage = Current x Resistance or V = IR.

Watt's Law is equally useful for finding out the relationship between power, voltage and current.

Watt's Law states that: Power (in Watts) = Voltage (in Volts) x Current (in Amps) P = V I.

Combining with Ohm's law we get two other useful forms: P = V*V / R and P = I*I*R Power is a measure of the amount of work that can be done with the circuit, like turning on a motor or a light bulb.