# Homework Help: Electric field in the center of uniformly polarized cylinder

Tags:
1. Aug 12, 2015

### gruba

1. The problem statement, all variables and given/known data
Hollow dielectric cylinder, with inner radius a, outer radius b, and height 2h is uniformly polarized by volume. Polarization vector is normal on the bases of a cylinder. Intensity of polarization vector is given, P. The surrounding area is vacuum. Calculate intensity of electric field in center of the cylinder (at point C)

2. Relevant equations
-Cylindrical geometry
-Polarization vector

3. The attempt at a solution
If approximated, intensity of electric field could be E= -P/ε0 (field between two oppositely charged planes). But, we don't know the exact values for dimensions of a cylinder. Could someone give a hint on this, I am stuck here for a while.

The result should be E= -Ph( 1/(√a2+h2)-1/(√b2+h2)) / ε0

Thanks for replies.

#### Attached Files:

• ###### image.PNG
File size:
5.4 KB
Views:
233
Last edited: Aug 12, 2015
2. Aug 12, 2015

### TSny

Certain parts of the surface of the cylinder will have an effective surface charge density due to the polarization.