Electric Fields

An electric field is an area surrounding a charged particle or object that can exert a force on other charged particles or objects. Although you cannot see an electric field, a non-contact force acts on a charged object when it enters the field.

A non-contact force is a force that acts on an object without physically touching it. Since charged objects don’t need to touch for forces to act on them, this force is considered a non-contact force.

Electric fields are typically represented by electric field lines, which are diagrams with arrows.

The field lines always extend:

  • outwards, away from positive charge
  • inwards, towards negative charge

The electric fields can be drawn like the diagrams below.

It’s important to note :

  • The direction of the field lines indicates the direction of the force that would act on a positively charged particle placed within the electric field.
  • The strength of the electric field is indicated by the spacing between the field lines. Wider spacing between the lines signifies a weaker field. Keep in mind that as you move farther from the charged object, the electric field becomes weaker. You can see this visually, as the field lines get further apart the further you get from the charged particle.

In the diagram below is the electric field between two opposite charges.

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