Home » Basic Electricity 101 » Basic Electricity 101 Video Series Part-1

Basic Electricity 101 Video Series Part-1

I wanted to start at the top with some basic electricity for everyone. If you have never had any experience with electricity than this series will be good for you to follow. Q: What is Electricity?     A:It’s a general term used to describe the presence or flow of an electrical charge.

For our purpose of we are just going to cover electricity as it relates to the artificially produced power that we have in the United States: 120/240VAC 60Hz.

Electrical Terms


VOLT: Voltage is measured in VOLTS and is abbreviated V, The electrical symbol for voltage is E but sometimes you will find it listed as V

AMPERE: Current is measured in AMPERES and is abbreviated A, The electrical symbol for ampere is I

RESISTANCE: The unit of measurement for resistance is the OHM and is abbreviated by the Greek capital letter Omega (Ω), The electrical symbol for Resistance is R

ELECTRIC POWER: Is measured  in WATTS and is abbreviated W, The electrical symbol for Electric Power is P

Video:Basic Electricity 101 Video Series Part-1

What Does It All Mean?

The perfect analogy to electricity is water flowing through a garden hose.  Electrons are like the water – they are atomic-sized units that flow through a metal wire.  Wire is like a garden hose – it is the path for the current to flow through

  • Current (I) is like the flow of the water – the more the current, the faster the flow of electrons
  • Voltage (E) is like the water pressure – the greater the voltage, the more pressure there is
  • Resistance (R) is like a crimp in the hose – the more resistance, the less current that can flow
  • Power (P) is the product of voltage and current (the water pressure x the the rate of water flow)

There are but two formulas that represent the relationship between these four quantities.  The formulas are called “Ohm’s Law”:


The Ohm’s law “pie” is the easiest way to remember the relationship between Voltage (E), Current (I), and Resistance (R).  Just remove one, and the two that are left show you the equation.  For example, remove the I, and you are left with E/R, and therefore,  I = E/R.  So the three equations from this are:

E = IR          I=E/R            R=E/I


P = EI  (and from that we can deduce that E=P/I  and  I=P/E)

E is measured in volts,  I is measured in Amps, R is measured in ohms, and P is measured in Watts.

So, for example, a 60 watt light bulb runs on our household AC power outlet, which is 120 volts AC.  Therefore, the current running through the the light bulb can be calculated as:

I = P/E = 60/120 = .50 Amp

This is an extended version that I like to carry with me, I made a copy of it and had it laminated and used it all the time.

Extended Ohms Law Pie Chart

Alternating Current

Alternating current or A/C is supplied from an alternating current generator or alternator. A/C flows first in one direction and then reverses and flows in the opposite direction. This change of direction is very rapid, on the chart below you can see it peaks up and down each peak is one alteration or half a cycle and the full cycle contains both the positive and negative peak. This happens 60 times a second for the standard home owner in the US, this is called it’s Frequency abbreviated as Hz.

A/C Sine Wave

I do want to recommend a book for anyone who is looking for more information about Electrical References. It can be found at hardware or electrical stores and might be found at the big book shops too.  If you do plan on buying it online help me out with a few dimes by buying it through my link. Thanks.



None found.
, , , , , ,


  1. Earnie Bradford says:

    I would like to ask a question. If I have a light and it is pluged into the wall am I drawning power or usage if I do not turn the light on. This means everything else in your house, should you plug everything in before you use it or do you only use power if you turn it on.

Leave a Reply

Your email address will not be published. Required fields are marked *


About Rick

I've been an HVAC/R Mechanic working in the Seattle area for over 15 years, specializing in the commercial service industry.. I’m also a Licensed Electrician & Gas Piping Mechanic and have numerous other trade related certifications. I’ve instructed at local trade schools and now continue teaching through this site.

Get on the list!

Sign up for updates from me, I hate spam probably more than you! I will never sell or share your info.
* = required field

powered by MailChimp!
You might also likeclose
- Privacy Policy