Electric and Magnetic Fields

The force between two point charges (Q₁ & Q₂ ) placed r meters apart in a vacuum is given by



where

These show the 'direction in which a free positive charge will move'.

The electric field lines between two parallel charged plates are parallel and run +ve to -ve

The electric field lines from a positive point charge lie in a 'star' pattern (pointing outwards)

the electric field created by a pont charge are referred to as 'radial' and are also 'inverse square'. The E-field strength decreases as 1/distance² . (So doubling the distance will QUARTER the field-strength.)

This occurs between two charged parallel plates. The E-field strength has the same value everywhere and is given by (V=Pd across plates and d= separation of the two plates.)

This is the charge required to raise the voltage across the capacitor by one volt. C=Q/V. Where Q=charge and V= potential difference. Unit: Farad (or Coulomb per volt)