# Electrical – The Field of Study That Deals With Electricity

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Electrical is the field of study that deals with electricity. It is a highly demanded field all around the world.

Some people choose to self-learn electrical engineering because of a passion for the subject. However, this can be difficult to accomplish, as it may require months or years of study. Thinking of this as a marathon rather than a sprint can help you keep your motivation alive.

## Electrons

Electrons are the negatively-charged particles that orbit around the positively-charged nucleus of atoms. This arrangement gives atoms their characteristic size and determines the chemical activity of elements.

In a conductor, accelerating charges (like electrons) give rise to electromagnetic waves that travel at a significant fraction of the speed of light in free space. These electromagnetic waves are the reason that current flows through conductors like wires.

While the paths that electrons take can be described mathematically, they are not well understood. This is partly because the very small particle has the smallest mass of any charged lepton, and so cannot be observed as it moves. Instead, scientists talk about the probability of finding an electron in particular regions of space, which they call energy levels. In semiconductor materials, current results from the movement of electrons across a gap between full energy states, which is created by a difference in electric potential energy. The electron’s antiparticle, which carries a positive charge, is called the positron.

## Atoms

Atoms are tiny particles that make up all matter. They are so small that they can’t be seen even with a microscope. A human hair is about a million carbon atoms wide.

The center of an atom is called the nucleus and it has protons and neutrons, which have positive electrical charges. Electrons surround the nucleus in precise shells. Usually, the number of protons and electrons in an atom is equal; this is called neutrality. But if an atom has more electrons than protons, it has a negative charge. If it has less electrons than protons, it is positively charged; this is called a cation.

The nucleus of an atom has the same mass as the whole atomic mass of that element, which is given by its atomic number in the Periodic Table of the Elements. However, an atom’s electrons have negligible mass. When an atom absorbs or emits a photon, its electrons can jump between energy levels in the closely packed electron orbitals. This is called quantum tunneling.

## Electricity

The electricity we use in our homes and offices comes from many sources. Some of it is generated at power stations using electric generators powered by burning fuel, nuclear fission, or water and wind turbines. Another source is solar cells, which turn the energy of sunlight into electricity.

Just like mass in a gravitational field has potential energy, charges at rest have electrical potential energy. When set into motion, this energy gives rise to the electromagnetic force described by Maxwell’s equations.

As electrons move along a wire in an electrical circuit, they create an electric field that influences all the other electrons that share the same wire. The electrons nearest the light bulb, for example, will start flowing one step faster than those farther away because of this field effect. This causes the bulbs to begin transforming energy from potential electricity into light (or heat). The same principle is used to power electric motors and heating elements.

## Circuits

A circuit is a closed path that electricity can flow through. It starts at a power source, goes through conductors to devices that use the current and then back to the source.

A device that uses electricity is called a load. If the load has a high resistance (like a light bulb) then it will have to work harder to get the current flowing through it. The bulb will be brighter if it has a lower resistance.

Electricity always flows in a loop, or circuit, and there are two types of circuits: series and parallel. (See the links at the bottom of this page for a more-detailed discussion of these differences.)

Control devices, like switches and relays, are needed to start and stop the flow of electrons in a circuit. They are usually mechanical, but can also be electronic. This makes it possible to change the connection between the source and the load, which allows current to do something useful like illuminate a light bulb or run an appliance. Star Plus Electrical