Is the C=εA/d Formula for a Parallel Plate Capacitor an Approximation?

[rshalloo]

Just wondering if the formula C=εA/d is a realistic formula for a parallel plate capacitor, surely its making an approximation about the plates being HUGE or that at the edges the electric field doesn't go in nice straight lines from one plate to the other?

If it is an approximation does anyone know the more accurate formula

 

[ComputerPsi]

Yes, it is an accurate formula. Why do you doubt it?

 

[rshalloo]

I just thought that effects at the edge of the plate would affect it slightly

 

[sahil_time]

It does affect. But i guess the error of not taking into account is negligible!
Its called fringe effect in capacitor.

 

[sardar]

?

The formula C=εA/d is a realistic formula for a parallel plate capacitor, but it is indeed an approximation. This formula assumes that the plates are infinitely large and that the electric field lines are perfectly straight between the plates. In reality, the plates of a parallel plate capacitor have finite dimensions and the electric field lines are not perfectly straight at the edges.

To account for these factors, a more accurate formula would incorporate the shape and size of the plates, as well as the distribution of the electric field between them. This can be done using numerical methods or by solving the Laplace equation for the electric potential between the plates.

However, the C=εA/d formula is still a useful approximation for many practical applications and can provide a good estimate of the capacitance of a parallel plate capacitor. It is important to keep in mind its limitations and to use more accurate methods when necessary.