## Visionary01 2 years ago Is a copper pipe consider to be a "closed" circuit?

1. Visionary01

Where Lenz's law is applied, when a magnet passes through a copper pipe, current is induced, and a magnetic field is created to oppose the magnet that created it.However, in a open circuit I = 0, thus there is no magnetic field, thus the magnet passes through it with no resistance. The only resistance acting on the magnet is friction?

2. Visionary01

Im guessing since a copper pipe is closed... Current can flow. And it cylinder shaped... Lenz law is effective and eddy current are generated to oppose the magnet. But in a coil that's circuit is open current can't flow, thus there is no magnetic field.

3. Visionary01

@Vincent-Lyon.Fr @Jemurray3 @ghazi @Shane_B @TuringTest

4. Eleven17

All you have to know that is that current will flow at all. If it down then there must be a "closed" circuit.

5. Visionary01

@Eleven17 so, a copper pipe is indeed a "closed" circuit. But if it was "open" like a coil in a "opened" circuit there will be no flow of current.

6. ghazi

first of all i would suggest you to think of circuit, what exactly circuit means then i am sure you wont think of copper pipe as circuit anymore :), if you think of it as a circuit can you state how?? it is not a circuit , current will flow from a low potential end to the high potential end across the pipe but , if you just think of pipe then its not a circuit. by the way its good to know you wonder about things and never let this thing go, keep wondering keep finding :D |dw:1369860572793:dw| current will flow across the surface from the terminals of potential difference

7. Visionary01

@ghazi thanks for the encouragement. But I think you did not understand my point... If we have coil like soi in a "closed" circuit: |dw:1369948755802:dw| No, if a magnet passes through that coil, lenz law will not be in effect. Because, I = 0, there is not magnetic field to oppose the magnet. Now in a copper pipe, if you drop a magnet through it, the magnet slows down because of the induced current's that created a magnet field opposing the magnet: |dw:1369948928253:dw|

8. Visionary01

sorry for using he "term" circuit it was wrongly used indeed! My question is, why does currrent flow through a copper pipe? Is it considered to be like a "cosed" loop? A coil in a circuit and a magnet passing through it has no current flowing because the circuit is "opened".

9. Visionary01

I think I've figured it out! Copper pipe is like a HUGE thick loop! so THERE INDEED is a path for current to flow! However, a loop that is opened will not have current flowing through it because of it not being closed!

10. Visionary01

Um... Am I right? @ghazi @Eleven17 ?