Van De Graaff Generator

[Samson4]

If you run a wire from the outside surface of the dome to the inside of the same dome, would it be possible to make a spark to the inside surface of the same dome?

 

[mfb]

With a conducting connection between the two parts? No. They will be at the same potential.

 

[Samson4]

How come? The dome is at a higher potential than the belt that's charging it.

 

[mfb]

Not at the point where the charges are extracted (neglecting the tiny resistances and current flow in the material).

 

[Samson4]

Okay, will this capacitor charge? The cap and ground are shielded from the belt and rotor.

 

[mfb]

How do you get a ground connection in the middle? If you take a cable out, it will charge.

 

[Samson4]

I just didn't want to clutter the diagram; but yes, a cable is going outside the dome to ground.

I was always told that the inside of the dome is neutral or had no potential.

 

[mfb]

It has no electric field - unless you add a connection to ground. That's not the same as no potential (which does not exist anyway - a potential can be zero but it cannot be nonexistent).