Let’s try to review the potential difference between two points in an electrical field before explaining what is electrical energy.
Suppose the potential difference between point A and point B is V volt.
Based on the definition of potential difference, we can say that if one positive electrical load unit that is a body that contains one – coulomb positive load travels from point A to point B, it will work v joules.
Now instead of charge of one – coulomb if q coulomb charge moves from point A to B, it will do vq joules work.
If the time taken to travel from point A to B by the q coulomb charge is t second, then we can write the rate of work done as
Again, the work per second is defined as power. In that case
In differential form, we can write
Charge passing through a cross section of conductor per unit time (second) is
It’s nothing but the electrical current i, through the conductor. So we can write,
If this current will flows through conductor for a time t, Then we can say the total work done by the charge is
We define this as electrical energy.
Electrical Energy Definition
Work done by electrical charge is called electrical energy. If current of I ampere is flow through a conductor having potential difference V volt across it, for time t second, the energy is
Electrical Energy Formula
The Expression of electrical power is
Electrical energy is
Unit of Electrical Energy
In general, we find that the electrical energy unit is joule. This is equal to one watt X one second.Commercially, we also use other electrical energy units, such as watt hours, kilo watt hours, megawatt hours etc
If one watt power is consumed for 1 hour, the energy consumed is one watt hour
Board of Trade Unit or BOT Unit or Kwh
The practical, as well as a commercial electrical energy unit, is kilowatt hour. The electrical supply companies are charging their consumers for electrical energy per unit per kilowatt hour. This kilowatt hour is a BOT unit (Board of trade).
Also Read- Ionization Energy