# What is effective conductivity?

1. Apr 21, 2012

### Xyius

What is "effective" conductivity?

In one of my homework problems (This ISNT a homework help question! It is conceptual) It says to find the "effective" conductivity.

What is the difference between conductivity and effective conductivity? Is there any difference?

2. Apr 21, 2012

### Bob S

Re: What is "effective" conductivity?

At higher frequencies, the depth of penetration of a signal into the center conductor of a coaxial cable is limited to the skin depth δ. See http://en.wikipedia.org/wiki/Skin_effect. So if the radius of the center conductor is r, then the effective conducting area is 2 πrδ, which is less than the total conductor area πr2.

3. Apr 21, 2012

### Xyius

Re: What is "effective" conductivity?

Thanks a lot!!

4. Apr 21, 2012

Staff Emeritus
Re: What is "effective" conductivity?

Is this AC or DC? Is this in simple or composite materials? What is the context.

5. Apr 21, 2012

### Xyius

I was given a wave traveling though a lossy dielectric medium in a transmission line. So this is AC.

6. Apr 21, 2012