Defining an Electric Field
- An electric field is defined as a region of space in which a charged particle experiences a force
- Hence, electric fields are a type of force field
- The charged particle could be stationary or moving, and will experience an electric force in that field
- All charged particles create their own electric fields
- These fields exert an electrostatic force, FE on other charged particles
The electrostatic force between two charges
- Like charges (positive and positive, or negative and negative) repel each other
- This means the force on each charge are away from the other charge
- Opposite charged (positive and negative) attract each other
- This means the force on each charge is towards the other charge
- The size of the force changes with distance
A repulsive force decreases with distance
Examiner Tip
Electric fields are slightly different in that a charged particle will experience a force in this field whether it's stationary or moving. Don't get this mixed up with a magnetic field, where a charged particle only experiences a force if it's moving.
