How is the magnitude of an electric field defined? Its direction?
Step 1 of 3 Electric field strength is a vector quantity.It has both magnitude and direction. The magnitude of the electric field is calculated as the force experiences per charge on any given test charge located within the electric field. The force on the test charge could be directed either towards the source charge or directly away from it. The direction of the force depends on nature of charge. The test charge must be positive by the convention because positive test charge is pushed or pulled when in the presence of the electric field. Step 2 of 3 A positive source charge would create an electric field that would exert a repulsive effect on a positive test charge. Thus, the electric field vector would always be directed away from positively charged objects.