conduction over a metal plate comapred to a wire?

Question

if you have a metal plate, or sheet of metal, and a similar wire (ie same material) what are the differences in terms of conduction, resistance, temperature rise etc.

I know that if "use a proportionately larger conductor. For example, using a #4 wire (suitable for 60 A at 90 C rise) [instead of a #10] to handle 15 A will result in an observed rise of approximately 22 C. Basically, doubling the conductor size is required to obtain a temperature rise of 25 percent of the original choice", and was simply wondering the effects of a similar experiment, except comparing a wire with a plate/sheet.

if that makes sense!

Answer 1

I think, if I remember correctly, this is how some ' Shunt Resistors ' are made. Kind of like a small sheet, or strip of metal. Some as long as four inches, and as wide as three inches. They pass the current through one end, and it exits the opposite end. So I have to think, if you expand the area you increase the resistance, and it is probably more likely the plate will heat up to a certain temp sooner than a wire made of the same material. This is only my best guess - I'm sure others will answer who know for sure.

Answer 2

Just think about the geometry and the path the current will take. You haven't described the circuit, so you'll need to work out the details yourself. But for example, if a meter of wire with a cross-section area of one square millimeter has a resistance of one ohm, then a one-meter long sheet of the same metal with the same cross-section area will have the same resistance, as long as the current is flowing through all of the sheet. If the sheet is also a meter wide and you make both connections at one edge, the resistance will be higher, since the current will not flow uniformly through the sheet as it does through the wire.

Answer 3

Assuming you're talking DC, it is all to do with the cross sectional area of the conductor. (If you're talking AC, then eddy currents make the question more complex.)

For a given material, if the cross sectional area is the same, then the resistance is the same, so for a given current flow, the same heat generation.

However, a plate conductor will dissipate heat into the surrounding air much better than a cylindrical wire.

Hence printed circuits are quite good at self-cooling, or rather are able to conduct more current than a wire of equivalent cross sectional area, without the same problems of temperature rise of the conductor (wire/printed circuit strip).

Answer 4

i did this years ago and so am out of date but there is a surface effect where electricity tends to flow in the outer surface of a cable and so this will be more effective if you use a flat plate of metal

Answer 5

Plates -------------------Power
Condensers
Shunts
Rectifiers
Faraday Cage
Spark Arrestors
Transmission and result varies with each.
Coat one side with zinc oxide and change A.C into Half wave D.C.
Can't help you, my mind isn't what it used to be.