Capacitors and electric field

[fwFAWFSERG]

REVIEWING OLD TEST and.. don't understand why you use the full distance.

Homework Statement

pretty much there's a home made capacitor made by two pie pans 3.5 cm apart. V is given Q is given, the question asks:
calculate the electric field halfway between the plates

Homework Equations

dV=Ed

The Attempt at a Solution

you just simply plug in, but why is distance the full 3.5 cm and not half of that, as youre finding the field at a distance that is halfway between the plates? am i answering my own question and the E field is constant?

 

[rock.freak667]

Yes, the electric field is uniform between the plates so it would be the same.

 

[nlightner]

There are a few things to consider when calculating the electric field between two plates of a capacitor. First, the distance between the plates is important because it affects the overall capacitance of the system. The closer the plates are together, the higher the capacitance will be. In this case, the distance of 3.5 cm is given and should be used in the calculation.

Secondly, the electric field between the plates is not constant. It is strongest near the edges of the plates and decreases as you move towards the center. However, if the distance between the plates is small compared to the size of the plates, the electric field can be considered approximately constant. In this case, the distance of 3.5 cm is small compared to the size of the plates and the electric field can be assumed to be constant.

Finally, when calculating the electric field halfway between the plates, it is important to remember that the electric field lines are perpendicular to the plates. This means that the electric field halfway between the plates will be at a right angle to the plates and will not be affected by the distance between the plates. Therefore, the full distance of 3.5 cm should be used in the calculation.

In conclusion, when calculating the electric field between two plates of a capacitor, it is important to consider the distance between the plates, the size of the plates, and the direction of the electric field lines. In this case, the full distance of 3.5 cm should be used in the calculation as it is small compared to the size of the plates and the electric field can be assumed to be constant.