# Physics Topic: Electric Field

Show an understanding of the concept of an electric field as an example of a field of force and define electric field strength as force per unit positive charge.

Represent an electric field by means of field lines.

Recall and use Coulomb’s law in the form F=Q

_{1}Q_{2}/4(pi)E_{0}r^{2}for the force between two point charges in free space or air.Recall and use E=Q/4(pi)E

_{0}r^{2}for the field strength of a point charge in free space or air.Calculate the field strength of the uniform field between charged parallel plates in terms of potential difference and separation.

Calculate the forces on charges in uniform electric fields.

Describe the effect of a uniform electric field on the motion of charges particles.

Define potential at a point in terms of the work done in bringing unit positive charge from infinity to the point.

State that the field strength of the field at a point is numerically equal to the potential gradient at that point.

Use the equation V=Q/4(pi)E

_{0}r for the potential in the field of a point charge.Recognise the analogy between certain qualitative and quantitative aspects of electric and gravitational fields.