On This Page
Overview
An electric field is a model that describes the electric influence around charged objects. Instead of only describing force between two charges, field language describes how space around a charge is affected. A charge placed in an electric field experiences an electric force.
The Field Concept
A field assigns a value to locations in space. An electric field assigns an electric force per unit positive charge to each point.
Field Direction
Electric field direction is defined as the direction of force on a positive test charge. Field lines point away from positive charges and toward negative charges.
Field Strength
Electric field strength describes how strong the electric influence is at a location. Stronger fields produce larger forces on charges of the same size.
Electric Field Lines
Field lines are visual tools. They show direction and relative strength, with closer lines representing stronger fields.
Uniform Electric Fields
A uniform electric field has the same strength and direction throughout a region. A common example is the idealized field between oppositely charged parallel plates.
Point Charge Fields
The electric field around a point charge spreads outward or inward radially, depending on the sign of the charge, and weakens with distance.
Connection to Electric Potential
Electric fields are connected to electric potential. A charge moving in a field can gain or lose electric potential energy depending on the direction of motion and charge sign.
Common Mistakes
A common mistake is thinking field lines are physical wires or paths that charges must follow. They are diagrams that represent field direction and strength.
Why This Matters in Physics
Electric fields connect charge, force, energy, voltage, circuits, capacitors, electronics, and electromagnetic waves.