No resistance Circuits

[mdjakhi]

Hi guys,
How do you use ohms law on a circuit with 0 resistance? So, assume there is 10Amps and 0 Ohms on a circuit, how would you find the voltage? (E=IR?)

Also assume you have a circuit with no resistance on it, where would be considered the return path? Like the potential difference I mean from hot to neutral.

 

[charlie76]

Ignoring for now weather it is or isn't possible in practice,
I always thought that to have a voltage ( or potential difference )
then you need current flowing between two points
with a resistance between these points.
this is what gives you potential difference or voltage
Am I correct or not ?
SO NO RESISTANCE CAN ONLY = NO VOLTAGE ?

No, you don't have to have a current flowing between the 2 points at all. The potential difference is the difference in potential between the 2 points. The potential to make a current flow between the 2 points. The resistance could be infinite between the 2 points and so no current is flowing but the potential still remains.

2 cables held apart one at 50V and one at 0V, there is a 50V potential difference between them. Touch them together there is now no resistance between the two ends (in a perfect conductor) measure the voltage now 0V as there is no potential difference, they are both at the same potential, 50V, current will now flow. Obviously the current is restricted to the supply source and the resistances in the circuit.

 

[Dangerous Brian]

CERN already use zero resistance conductors for the magnets in the LHC. This link explains a bit about superconductivity,
Superconductivity, Superconductivity - http://hyperphysics.phy-astr.gsu.edu/hbase/Solids/scond.html

 

[stummish]

I didn't realise CERN has 0 resistance conductors. I know they cool it (gold? conductors) down to a few degrees off 0°K. If I had the time I'd look it up, interesting forum topic this has turned out to be!

 

[Des 56]

It has been said that Superconductivity at room temperatures remains a very very very distant prospect (if it ever has been considered a prospect or even possible in the first place)