There is no fixed definition for Electricity at all.
* Electricity is a form of Energy.
* Electricity is flow of electric charge or power.
*Flow of electrons.
Let us take a closer look at “electricity” conceptually and get to know it.
All matters are formed of atoms and each atom contains a nucleus with protons and neutrons. Protons are the particles who carry positive charge where neutrons do not carry charge. This nucleus is surrounded by electrons which carry negative charges. Generally, number of protons in an atom is equal to number of electrons. However, sometimes an atom may lose or gain electrons. In this case, there occurs an energy due to flow of negative charges(electrons).
Electricity is basically a part of nature and one of the most common used energy types. However, it is not a primary energy source but a secondary. Which means, we generate energy by using primary sources found on the Earth such as coal, natural gas, oil, nuclear power and other natural sources. There are several ways to generate Electricity which will be the topic of another post. (Generating Electrical Energy).
Before the generation of Electricity began, Houses were lit by using kerosene lamps (ker-osene). Moreover, people used to warm rooms by using wood-burning or coal-burning stoves or they used to store foods for a long time in iceboxes. Benjamin Franklin’s experiment (A.K.A Kite Experiment) changed the whole understanding on electrical energy and lightning. In this Experiment, Benjamin Franklin proved the connection between lightning and electricity. (More on Kite Experiment) After this experiment, Electricity concepts began to be understood.
Main types of electricity.
There are mainly two types of electricity which are static electric and current electric. Basically, static electric is the case when electrical charges are collected on the surface of a material. This kind usually occurs by rubbing two materials into each other. Consider a balloon and wool. At the beginning, both of them are neutral since the number of positive charges equal to the number of negative charges. When we rub them to each other for a while, the balloon will become negatively charged and the wool will become positively charged due to transfer of electrons from wool to balloon. Therefore, the balloon will attract materials like paper.
There is a list that shows which materials tend to be charged positive, negative or neutral. Thanks to that list, it is possible to make greater combinations for creating static electricity. We call this handy tool that helps us to find the best combination as “Triboelectric Series”. (Triboelectric Series).
The second kind of electricity is current which is the rate of flow of electrons. It is generated by moving electrons and the unit is Amperes. From the definition, the unit may be defined as one coulomb per second (note that coulomb is the unit of charge). Unlike the static one, current must flow through a conductor. The current enables us to calculate the energy and power needed. We can easily observe the transformation of energy from a point to another by using current electricty.
Think of a tap, a sink and a water hose. In this modelling, the water is the charge. If the water is collected on the sink, that is static electricity because we cannot use it effectively and it cannot move. If we connect a hose to our tap, so that we can carry our water wherever we want as long as we have the proper hose. That is the current electricity. Additionally, Notice that water flows through the hose which is just like the current flows through wires.
In our courses on Circuit Analysis, we will mainly talk about current electricity. There are two kinds of electric current which are Direct Current (DC) and Alternative Current (AC). The main difference between AC and DC is that, in DC current only has one direction. However, in AC, the direction of current changes periodically.
The song of the text : https://www.youtube.com/watch?v=VCfgXHLCKNY