Electric Field between Two Parallel Plates

The electric field between two parallel plates is uniform. The field lines are parallel to each other and at right angles to the plates. The electric field strength is equal to the potential difference between the plates V divided by their distance apart d.

E

=

V d

F=QE and E=V/d, so it follows that F=QV/d.ExampleA pair of parallel plates 50mm apart connected to a constant 8000V high voltage supply:E=V/d = 8000/50×10^-3
=160,000Vm^-1
The force on a charge of 9.6×10^-19C is given by:F=EQ = 160,000×9.6×10^-19
=1.54×10^-13N