Allegedly uniform field in a capacitor


“Because the electric field is uniformly spread over the plates ….”

“Electricity and Magnetism” by B I Bleaney, Lecturer in Physics, St. Hugh’s College, Oxford, and B Bleaney, Fellow of St. John’s College, University Demonstrator and Lecturer in Physics, Oxford, pub. Oxford Clarendon Press,

1957 p236; 1965 p256


Maxwell’s equations of the electromagnetic field

….  ….

1957 p238; 1965 p258

….  ….

If for simplicity we take a parallel plate condenser with plates area A, surrounded by a guard ring, the field between the plates is uniform, and the displacement D has the value D=q/A, where q is the total charge on the positive plate.

….  ….




“Fundamentals of Physics” by R Resnick and J Walker,  pub. Wiley 2001, p761


“32.10 Displacement Current

“…. Assuming that the electric field E between the two [capacitor] plates is uniform …. …. Because the electric field is uniformly spread over the plates, the same is true of this fictitious displacement current ….”


Discussion of from

This looks further into the evidence for the fact that text book writers including Bleaney have always thought the field between the capacitor plates is uniform.