Electric basics. Article:

How does Electricity works.


What is Electricity?

Electricity involves the making and using electrical energy. In Electricity, we often talk about current, voltage and resistance .

Current is the flow of electrons in the same direction and voltage is the force which pushes electrons to flow in the same direction or we can say it is the force which cause current.

What are Electrons.

Anything on earth is made up of atoms, including conducting materials used in electrical engineering. An atom consist of protons, neutrons and electrons.

Protons and neutrons are contained inside the nucleus of an atom, they don't move. Electrons orbit around the nucleous of an atom as shown in the following diagram of a Heliun atom.

Helium atom

helium atom

In conductors electrons are loosely held by the nucleus of an atom, they can easily jump from one atom and begin to orbit on the shells of another atom.

To constitute current electrons must move from one atom to another in the same direction and also for electrons to move in the same direction, they need a force of voltage which push them to move in the same direction.

What type of force is Voltage.

If we have two bodies, the one with an excess of electrons and other with a deficit(shortage) of electrons.

Since like charges repel each other and unlike charges attract each other, in the body with an excess of electrons they is a repellent force between electrons themselves, and in the body with a deficit of electrons, they is a force of attraction of electrons by protons.

If the two bodies a connected together through a conductor, electrons will flow from where they are in excess(high potential) to where there is a deficit of electrons (low potential).

The force of attraction and repulsion in the bodies constitute voltage just as between positive and negative plates of a battery.

DC and AC Electricity.

Electricity is generated in two forms, either as Direct current(DC) or Alternating current(AC).

Direct current DC.

Direct current is a type of electricity in which electrons flow in only one direction, the voltageand current does not vary in magnitude. It is the one produced by solar panel, dc generators and stored by batteries.

Direct current graph

Alternating current AC.

Alternating current is a type of electricity in which electrons reverse direction of flow and the voltage and current in AC varies in magnitude regularly.

This type of electricity is produced by AC generators known as Alternators. In the diagram below the positive parts of a graph shows a forward direction and negative parts shows a reversal in direction of flow of AC.

Also in the diagram you can see that the curving line showing the AC values is flactuating between zero and maximum positive and negative values, this shows that the AC varies in magnitude.

Alternating current graph

AC is usually used in transmisition of electrical energy because it is easy to change its characteristics, it can be easily stepped up and down with the help of transformers to reduce loss of electricity during transmission.

DC is mostly used to power small electrical gudgets like cellphones since they contains some electronic components which need a steady supply of current and voltage.

Laptops, cellphones chargers convert ac to dc, so that electronic components of these items get a steady supply of current and voltage.

In electrical, electrons follow a paths when flowing and this paths is called a Circuit.

A Circuit in general is a paths which electrons(current) follows when flowing, electrical components like lamps are connected to a circuit so that electrons can pass through them.

When electrons pass through a circuit component, the materials making up the component will start to behave in other ways which we need in electrical engineering, for example when electrons pass through a filament lamp, the filament heat up and produce light.

A circuit can be Open or Closed, but to have current in the circuit, the circuit must be closed. Switches used in electrical, their main purpose is to close or open the circuit.

A circuit posses various properties such as resistance, inductance, capacitance, and more which affect the flow of current. In this article we will focus mainly on resistance.

Resistance is a property of a circuit which oppose the flow of electrons or it is the opposition to flow of electrons(current is the flow of electrons) due to bonds between electrons and protons and also collision between electrons themselves as they make their way through a complex structure of a conductor.

In a purely resistive circuit (a circuit with only a resistance property), resistance determine the amount of current in a circuit with respect to the applied voltage.

The Relationship Between Voltage, Current, Resistance, Power and Energy.

As we have already talked about voltage, current and, resistance. Current is measured in ampares by an instrument called an Ammeter.

One ampare is equal to 6 240 000 000 000 000 000 electrons passing through any given point within a circuit in every second, the ammeter counts the number of electrons passing through it in every second and display them in ampares on the screen.

With this information on how current is measured, the other definition of current can be said: "Current is the rate of movement of electrons(charge).

Resistance is measured in ohms using an instrument called an Ohmmeter and Voltage is measured in volts using an instrument called a Voltmeter.

All the instruments we talked about can be contained in one instrument called a Multimeter. Units anables us to understand the quantities of an electrical quantity we are working with so that the risk of electrocution is minimized.

Electrical Energy and Power.


Power is the rate at which works is done or the rate at which energy is converted, power is measured in watts. We can also say it is the amount of work done or energy converted in one second .

You yourself under some circumstances, you know at what time howfar will you be on a certain job, this depends with your power.

In Power, we are finding out how much energy is converted in every second, the formula for power is energy divided by time in seconds.

In electrical we can also find power by multiplying current by voltage flowing in a circuit in every second.

Power = Energy ÷ time Power = Voltage × Current


Energy is the ability or capacity to do work. For example you yourself, you know that you can complete a certain job or not, this depend with the total energy you have at that moment.

Energy is measured in joules or in watt-second more in electricity, 1 joule = 1 watt-second.

When finding electrical energy we usually multiply power by time in seconds. In the formula power is the rate at which one does a job or the rate at which one will do a job and time shows how long the job has been done or will be done, to come up with energy.

Energy= power ÷ time

As we have already said, Energy is measured in joules or mostly in watt-second in electrical, but if working with large amount of energy the kilowatt-hour is used.

One Kilowatt-hour(1 kWh) is often called a Unit in electrical. Most electrical supply companies charge their consumers in kilowatt-hour.