Lesson 01 – What is electricity?

This answer can be very complicated but for our focus we are going to keep it as simple as possible.  An electron is a very small entity with a negative charge circulating a nucleus of protons in an atom. Electricity is the flow of electrons from a negative pole or charge to a positive pole or charge through a conductor. 

A Conductor is a material that allows the flow of electrons trough it and all metals are good conductors, on the other hand an insulator is a material that doesn’t allow the flow of electrons through it like glass or plastic. Resistance is the measurement of the ability of electrons to flow through a material.

Electrons can’t move on their own through a conductor and they are moved by an attractive force which is an electromotive force called voltage to pull the electrons from one place to another. The flow of electrons through the conductor is referred to as an electric current

That is great and everything but how can we interpret electrical current, voltage and resistance in an understandable way that everyone can understands? The best way to understand it is to use the following:

Electrical Current – Think of electrical current as water flowing through a pipe. The pipe can be small in which case only a small amount of water will flow through it or it can be a big pipe allowing a big amount of water flowing through it.

Voltage – The pressure under which the water flows can be seen as the Voltage, if the water pressure is low the water will just flow out of the pipe but if the water pressure is high the water will gush out of the pipe.

Resistance - The diameter of the pipe can be seen as electrical resistance. A pipe with a small diameter will have a higher resistance than a pipe with a big diameter. A tap in the pipe can be seen as a variable resistor where the water flow can be restricted to zero.


 What are the different types of electricity?

  • Static electricity - rubbing two surfaces together like a hairbrush through your hair creates two opposite charged surfaces, bringing these two surfaces together again can result in a electrical spark jumping over from one surface to the other. The electricity created in this way is known as static electricity. Lightning is the ultimate in static electricity and huge amounts of energy can be generated.
  • Direct Current (DC) – is the flow of electric current in one continuous direction from negative to positive. Batteries is a DC  source but power supplies can also supply DC.
  • Alternating Current (AC) – is the flow of electric current in alternating directions normally changing direction 50 or 60 times per second. A cycle is the flow of current from zero to a maximum in one direction back to zero and then in the opposite direction to a maximum and then back to zero again. The frequency of AC current is 50 or 60 Hz, that is 50 or 60 cycles per second. The power utility companies supply AC power and there are many reasons for that one being that AC power can be passed through transformers.