Inserting a steel rod into a current-carrying copper pipe

[orzyszpon]

<< Mentor Note -- thread moved from the technical forums, so no Homework Template is shown >>

The situation is as follows: Current I flows along the axis of the copper pipe. From Ampere's law, the magnetic field inside the pipe is zero and is equal to μ0*I/(2π*r) outside the pipe. Now, an unmagnetized steel rod is inserted into the hollow pipe. What, if anything, happens?

 

[berkeman]

The situation is as follows: Current I flows along the axis of the copper pipe. From Ampere's law, the magnetic field inside the pipe is zero and is equal to μ0*I/(2π*r) outside the pipe. Now, an unmagnetized steel rod is inserted into the hollow pipe. What, if anything, happens?

What are your thoughts?

 

[orzyszpon]

I think that nothing will happen. The steel rod is inserted into a field-free region, and the rod itself is unmagnetized. Had it been magnetized, it would have induced currents in the copper pipe that would have produced a magnetic field opposing the motion of the steel rod. However, the steel rod is not magnetized here, and I wanted to hear from the learned audience at the Physics Forum.

 

[berkeman]

I think that nothing will happen. The steel rod is inserted into a field-free region, and the rod itself is unmagnetized. Had it been magnetized, it would have induced currents in the copper pipe that would have produced a magnetic field opposing the motion of the steel rod. However, the steel rod is not magnetized here, and I wanted to hear from the learned audience at the Physics Forum.

Your thoughts seem okay so far to me. Is this a schoolwork question?

 

[orzyszpon]

Yes, it is a schol-related question asked of me by a high-school teacher with regard to a student project. I wonder whether there is anything I am not seeing that would upset what seems like a logical thread of thought. I can't see Lenz's law operating here. Thank you for your interest.

 

[berkeman]

Since it is for schoolwork, I'll go ahead and move this thread to the schoolwork forums.

 

[berkeman]

When will you be able to check your answer?

 

[orzyszpon]

We are the answer. There is no cavalry coming.