The Electric Field
We can describe the electric force on a charge q as the result of an electric field, E,
F = E q
Consider the force on a small "test charge" in the neighborhood of a positive charge Q.
Move the small "test charge" q around and investigate the force F that it experiences at different places near Q.
We will find an electric field originating on a positive charge.
Likewise, we will find an electric field terminating on a negative charge.
Electric Field Due to a Point Charge
Remember that the electric force is given by Coulomb's Law,
This electric force F can also be described in terms of the electric field E,
The electric field E due to a point charge Q is given by
Remember, the electric field E is still a vector!
What is the electric field a distance of 1 m from a positive charge of 1 C?
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(c) Doug Davis, 2002; all rights reserved