×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# current distribution

## current distribution

(OP)
anybody can tell me (1)why are currents concentrated on the edges of planar structures (for example: the fringe of the disk monopole) but not the whole area of planar structures? (2)what is the charge distribution along a metal rod?

### RE: current distribution

All of this is related to "skin effect". Basically, for high frequency, the magnetic shoves the electric field to the edges and surfaces of the conductor. Do a search on "skin effect", and you will find lots of Vector math expressed with Maxwell's equations.

### RE: current distribution

The second part of your question, about the charge density on the metal rod, does not have a simple answer. The charge density is highest where the electric field is highest and the electric field is highest at the pointy ends of the rod. I don’t think you can get a simple equation for the answer. It is probably an integral with no closed form solution and would normally be solved nowadays by direct simulation.

Static charge distribution has nothing whatsoever to do with skin effect (a dynamic phenomenon.)

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!