What is the Surface Charge Density on a Long, Uniformly Charged Cylinder?

In summary, the conversation discusses finding the surface charge density on a very long, uniformly charged cylinder with a radius of 5cm, given an electric field intensity of 100 kV/m at a radius of 1m. The suggested method is to use the Gauss' law for D and the definition of sigma for the geometry of the cylinder.
  • #1
Dan104
1
0
Hi, I would appreciate is someone could help me figure out this problem:

The electric Field Intensity in free space from a very long, uniformly charged cylinder of radius 5cm is 100 kV/m at a radius of 1m. What must be the surface charge density on the cylinder?

I've tried using different equations, but the only one that seems to get me somewhere, yet nowhere is D = eoE. please, can someone help??
 
Physics news on Phys.org
  • #2
Since you're using D, I'm guessing this is a linear dielectric problem, and you're looking for the bound surface charge. If that's right, just use the gauss law for D. Use D= [tex]\epsilon_0[/tex] E to get E in the vacuum outside the cylinder.

Edit:

and then use [tex] \sigma_b = P \cdot \hat n[/tex] to get the bound charge.
 
Last edited:
  • #3
I suggest you to use the Gauss' law for a portion [tex]L[/tex] of the cylinder:

[tex]E \cdot 2 \pi r L=\frac{Q}{\epsilon_0}[/tex]

and the definition of [tex]\sigma[/tex] for your geometry

[tex]\sigma=\frac{Q}{2\pi R L}[/tex]

(R - cylinder radius anr r - distance from the cylinder axis to the point where E is evaluated)
 

What is electric field intensity?

Electric field intensity is a measure of the strength of an electric field at a given point. It is defined as the force per unit charge experienced by a small test charge placed in the electric field.

How is electric field intensity calculated?

Electric field intensity is calculated by dividing the electric force acting on a test charge by the magnitude of the test charge. It is also influenced by the distance between the two charges and the permittivity of the medium.

What are the units of electric field intensity?

The SI unit of electric field intensity is newtons per coulomb (N/C). However, it can also be expressed in volts per meter (V/m) in the CGS system.

How does electric field intensity differ from electric potential?

Electric field intensity and electric potential are related but not the same. Electric field intensity is a vector quantity that describes the direction and strength of an electric field, while electric potential is a scalar quantity that describes the potential energy per unit charge at a given point in the electric field.

What are some real-world applications of electric field intensity?

Electric field intensity is used in a variety of applications, such as in the design of electronic devices, the study of atmospheric electricity, and in medical imaging techniques like electrocardiograms. It is also important in understanding the behavior of charged particles in electric fields and in the development of renewable energy technologies.

Similar threads

  • Introductory Physics Homework Help
Replies
26
Views
424
  • Introductory Physics Homework Help
Replies
17
Views
285
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
659
  • Introductory Physics Homework Help
Replies
13
Views
925
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
714
  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
898
Back
Top