Consider a very long, straight wire of uniform positive charge density. in the space below, describe the electric field of the wire. in particular, what direction does it point? does its strength depend on position? if so, how? note any symmetries of interest.

The wire is very long, which in the world of high school physics we treat as infinitely long. We would use Gauss' law to derive an equation giving the electric field strength at some point away from the wire:

E = λ/(2πε₀r)

E = electric field strength, λ = linear charge density, r = distance from wire

We can see from this equation that the field strength is dependent on the distance from the wire; the field strength is proportional to the inverse of r.

We should also note the very special symmetry of the electric field around the wire: The field points radially outward from the center of the wire.