1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Spring in a magnetic field

  1. Feb 16, 2014 #1
    1. The problem statement, all variables and given/known data

    A mass is attached to a spring through which circulates an electric current. Will the mass move?

    2. Relevant equations

    F = I l [itex]\times[/itex] B ?

    3. The attempt at a solution

    A spring is geometrically equivalent to a solenoid. Therefore, the current would generate a magnetic field which goes through the spring. What I'm not sure of is whether this magnetic field exerts a force on the solenoid or not.

    Thank you.
  2. jcsd
  3. Feb 16, 2014 #2


    User Avatar
    Science Advisor
    Homework Helper
    2017 Award

    Consider what F = I l × B of a small section of the spring does on the current in the next loop of the coil. What is the direction of the resulting force ? (Ideal) springs are supposed to extend/contract in repsonse to forces in which direction ?

    Problem formulation is somewhat vague: was the current there when we opened our eyes, or was it switched on at that moment ?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted