Homework Help: How do I calculate Volts per cm (V/cm) with the following given?

1. Sep 19, 2009

HMS-776

1. The problem statement, all variables and given/known data

How do I calculate Volts per cm (V/cm) with the following given?
Two coaxial tubes with 20kV placed across them.
Inner tube (actutally solid rod) has an OD of .5" and a length of 4"
Outer tube has an OD of 1.00" and a length of 4"

2. Relevant equations

3. The attempt at a solution
I was going to calculate the Area of the inner and outer tubes and convert them to cm, then divide the total area by the applied voltage? Somehow I don't think that is right???

2. Sep 19, 2009

Staff: Mentor

I'm not understanding the problem statement. Why would you have two coax cables with a net voltage between them. Usually the shields of each coax will be at ground potential, or somebody is about to lose their job...

3. Sep 19, 2009

HMS-776

They are just coaxial tubes (one inside the other) which form a capacitor. Sorry if I explained that wrong.