Electromagnetic Field

Since all charges, moving or not, have fields associated with them, we must have a way to describe the total field due to all randomly distributed charges that would be felt by a positive charge, such as proton or positron, at any position and time. The total field is the sum of the fields produced by the individual particles. This idea is called the principle of superposition.

Let us look at arrow or vector representations of the fields from some particular charge distributions. There is an infinite number of possibilities, but we will consider only a few simple cases.