Electricity plays a critical role in many of the world’s most important technologies. From the electric telegraph to microchips, this dynamic energy begins with electrons moving through metal wires.

Most electricity is generated at power plants using various energy sources to spin turbines that energize copper wire coils. This wire conducts electrons through closed circuits, delivering energy for homes and factories. Contact Jacksonville NC Electric now!

Electrons are subatomic particles with a negative electric charge that give rise to and interact with the electromagnetic force, one of the four fundamental forces in nature. They are a key component of conductors, and it is the interaction between these electrons and the electromagnetic force that gives rise to current flow.

Electrons move based on the relative strengths of their magnetic fields and the energy they have (in their lowest, uncharged state). This process is called “radioactivity”. The electron has an intrinsic angular momentum (spin) that has a half-integer value, defined by the Pauli exclusion principle. Electrons belong to the fermion particle family and are also referred to as leptons.

In atoms, electrons fill up certain regions of space around the nucleus, called orbitals. Each orbital is shaped differently and can accommodate only a limited number of electrons, depending on the element. Generally, the inner shells fill up before the outer ones, but it is possible for an atom to have more than one electron in its outermost shell.

The valence (outer ring) electrons are what allow an element to conduct electricity. This is because these electrons can be ejected with relatively little energy from an atom by applying an electric force to it. It is these properties of electrons that lead to the phenomena of lightning and why ancient people noticed that amber attracted small objects after it was rubbed.

Potential

The electric potential is the energy of a point charge in an electric field. It is a scalar quantity that has only magnitude and no direction; in contrast to the electric field, which is a vector quantity. It may be viewed as analogous to height: just as a released ball will fall through the difference in elevation of two points, a charged particle will move through an electric potential gradient.

In classical electrostatics, the electric potential is given by the equation (V 4pow(q, r)). The SI derived unit of electric potential is the volt (in honor of Alessandro Volta), which is also sometimes referred to as the Galvani voltage or the fermi potential, and was historically part of the centimetre-gram-second system of units.

The electric potential of a charged object depends on its position and the location of other charges, not its own charge. This is why it is possible to make a battery or other source of electricity produce different voltages at its terminals, depending on the arrangement of other components in the circuit. The potential at any point in a conductor is equal to the electric potential of the other end of the conductor if they are connected through negligible resistance wires. The potential at any other point is equal to the energy that would be needed to bring a test charge from infinity to that point against the force of gravity.

Current

The rate at which charges move past a point in a conductor is known as current. This is a physical quantity that can be measured and the unit used to measure it is called ampere, abbreviated to Amp. A current of 1 Amp represents 1 coulomb of charge passing through a cross section of wire every second.

Students will probably be familiar with metals being good conductors of electric current and with the naming convention that says when a current flows through a wire that the ends are labeled positive and negative. But this is not a perfect picture of how current flows.

In fact, a wire with current flowing through it does not necessarily have to go all the way around a circle (though it will). And in a circuit the direction of current flow can be reversed. The fact that physicists originally chose to name a wire’s positive and negative ends is somewhat arbitrary but it makes it easier for us to talk about electric current and the movement of charge carriers.

Normally the motion of free electrons in a wire is haphazard and they do not channel themselves to flow in one direction. The force that can overcome this randomness and cause current to flow is known as voltage. In the case of a battery this voltage is supplied by electrochemical reactions inside the battery cell.

Conductors

If something is a conductor, it allows electricity to flow through it. Metals are common examples of conductors. The human body is also a conductor. It offers a resistance-free route for current to travel from a power source (the electrical wire) through it to the load, which consumes the electric energy.

The electrons in conductors are loosely bound to the atoms, which means they can move easily between different atoms. Metals generally have the best electrical conductivity. They are often used for wiring. Some of them are even superconductors, meaning they have zero resistance at very low temperatures.

Most organic molecules are insulators, but some can become conductors if they’re doped with small amounts of other elements or if they contain certain impurities. Water, for example, is an insulator when pure, but it conducts well when contaminated with salt and other dissolved substances.

Electrons in a conductor can move around pretty quickly, although they don’t actually travel at the speed of light (which is about 186,000 miles per second in a vacuum). This is because the surrounding air slows their motion, and atoms themselves can experience some friction. The electrons do need a finite amount of energy to be nudged from their valence bands into their conduction bands, however. This energy is supplied by the electrical voltage or thermal effect that causes one of them to be excited.

Voltage

A voltage is the difference in electric potential between two points. It is also called electrical pressure or electric tension. It is the amount of energy needed to move a charge from one point to another through a static electric field. Voltage is not to be confused with electrochemical potential, which exists inside structures with junctions of dissimilar materials and cannot be measured directly by a voltmeter. The SI unit of voltage is the volt, named after Italian physicist Alessandro Volta, inventor of the voltaic pile, possibly the first chemical battery. 1 volt is equal to one joule of work per charge.

Most electricity is produced in power plants, where a variety of energy sources are used to spin turbine shafts. These shafts in turn turn electromagnets surrounded by heavy coils of copper wire, creating magnetic fields that cause electrons in the wire to move from atom to atom. This movement of electrons is what we call electricity, and it travels through high-power transmission lines on tall towers.

As the electricity gets closer to where it will be used, its voltage must decrease. Different kinds of transformers at utility substations do this job, boosting or “stepping down” the electricity’s voltage. The electricity is then sent through overhead or underground distribution lines to homes and businesses.

It is important to understand the relationship between current, resistance, and voltage because most electronic devices are designed to operate at specific voltages. If a device is exposed to too much voltage, it may be damaged or rendered useless. Conversely, a device operating at too low a voltage may not be able to operate properly.

Power

Students have plenty of experience using devices that rely on electric circuits for their operation (torches, mobile phones, iPods). They also likely have a sense that you need something like a battery to make them ‘work’ and that batteries can go ‘flat’.

The science behind what happens is much more complex, but it is not a mystery for students to understand when presented with the right models/metaphors/analogies. In fact, a good model/metaphor/analogy is one of the most important tools for understanding electric circuits.

Electrostatic energy is a type of potential energy that builds up on non-conductive materials, such as wool and human hair. It can be transferred to other substances by friction, and it can cause a spark when the two surfaces are touched together. It can also be converted to electrical energy in the form of alternating current by an electric generator or battery. This electrical energy can then be used by a device to do work, such as turning on a light bulb or spinning a turbine.

The electrical energy produced by a source is measured in watts, which was added to the International System of Units in 1960. Larger systems are rated in terms of kilowatts, megawatts or gigawatts. Electricity is delivered to households through overhead or underground distribution lines and arrives at homes via transformers that reduce the voltage to a safe level for use in appliances and lights.