Before you study this lesson about electric potential (EP), make sure you understand the lesson about electric PE.
PE stands for potential energy. To avoid using potential energy too many times, we will PE from time to time.
Furthermore, we will use EP to refer to electric potential.
Make sure you don't confuse EP with electric PE!
In the lesson about electric PE, we defined electric PE using a single positive charge as shown below.
There is nothing special about using one charge. We could in fact use two, three, or as many charges as we want.
If we use four positive charges instead one, the magnitude of four charges is higher than that of one. This makes sense since you will have to do more work to move these four charges closer to the charged rod.
Say for instance the electric PE of one charge was 5 joules. Then, the electric PE of using two of such a charge will be 10 joules.
By definition, the EP is the electric PE per charge
The EP will thus have the same value at any point in an electric field.Here an example to illustrate this. Say for instance we place a positive charge in an electric field.
Why did we have to establish a difference between EP (electric potential ) and electric PE? In electricity, we prefer to work with the electric PE per charge rather than dealing with the total electric PE.