Distribution of current in a conductive plate

[papernuke]

There's a circuit with voltage source V resistance R and current i.
One section of the circuit has a conductive 'plate' element, connected like this:

-----wire-------metal plate------wire----rest of circuit

How does the current through the plate vary within the plate? I'm fairly certain the current would decrease as you moved up or down away from the axis of the wire, but decrease in what manner?

 

[K^2]

The current density distribution is actually going to be quite complex. The current exiting the wire would spread out, and then bunch up together before entering the other wire. The total distribution is such that it minimizes the net resistance of the metal plate. Solution will depend on geometry and resistivity of the plate. And I'm not sure if there is an analytic solution or if you have to do this one numerically.

 

[papernuke]

Is there a way to physically determine current in a small section of the plate? Would it work to simply to touch the leads of ammeter to the plate, a small distance apart?

 

[K^2]

Nope. You'd alter the current flow dramatically if you do that because ammeter has very low resistance. But if you touch the needles of a voltmeter very close together on the plate, you can get a good estimate of the current flow between these two points by using the resistivity of the metal in question.

 

[papernuke]

Oh, right
Thanks for the help!