Force on a conductor in a magnetic field

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BlackWyvern
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Homework Statement


Bill knows that a solution with an ionic salt dissolved in itwill allow a current to flow. Bill finds this quite interesting, so he finds a piece of plastic tubing and hangs it from an apparatus. He pours seawater into the tube until it is full. He then moves a magnet around the tube. Bill then uses a cell to create a current in the solution. Will a force act on the tube? Explain your answer.


Homework Equations


F = BIL


The Attempt at a Solution


I have no idea. I'm not sure if F = BIL only applies to electron flow, or ion flow as well.
 
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BlackWyvern said:
I have no idea. I'm not sure if F = BIL only applies to electron flow, or ion flow as well.
Nope, F=BiL works for all currents :smile:
 
You sure, got some proof? It is a bit far-fetched to just take someone's word for it. Because as far as I know, in electron flow, only electrons move. Whereas, in ion flow, cations and anions both flow in different directions.
 
BlackWyvern said:
You sure, got some proof? It is a bit far-fetched to just take someone's word for it. Because as far as I know, in electron flow, only electrons move. Whereas, in ion flow, cations and anions both flow in different directions.
Indeed cations and anions flow in the opposite directions; however, the question states that there is a current flowing, this means there must be more cations flowing than anions [or vice versa]. Since we have a current, we have a force...