1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    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!

Magnetic Induction Problem

  1. Mar 20, 2006 #1
    Ok there are two plastic rails over which a metal wire is kept , the wire is kept prependicular to both plastic rails , over the rails.. The coefficient of friction is 'n' between the metal and the plastic . The mass of the plastic wire is 'm' , Calculate the magnitude of the Magnetic field B , which just allows the wire to move.

    I equate dthe net frictional force which will try to limit the motion , with the Magnetic force given by ILB , but in the answer instead of 'n' . there is some square root fuction of 'n'in the denominator and n in the numerator. , please help.
     
  2. jcsd
  3. Mar 20, 2006 #2

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    The wire will feel no force at all unles there is a current going through it. What information do you have about the current in this wire? I'm assuming this is not a magnetic wire (not iron or cobalt)?
     
  4. Mar 20, 2006 #3
    ok the current in the wire is 'i' .
     
  5. Mar 20, 2006 #4

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    I assume there is also an "L" given. In that case you are exactly right. B=('n'mg)/(IL)
     
  6. Mar 21, 2006 #5
    but the answer is given to be : nmg / (IL)[sqrt(1+n(^2)]
     
  7. Mar 21, 2006 #6

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    What level of physics is this? High school or college, and is it calculus based? Are you using differential equations?

    I can not think of any reason why increasing the coefficient of friction should decrease the required magnetic field to start moving an object by the lorentz force. This is either an advanced, peculiar property I don't know about, or a mistake.

    ANyone else want this one?
     
    Last edited: Mar 21, 2006
  8. Mar 21, 2006 #7
    I am in my first year at a tech-school , and this is Physics-II which we r taught in the second semester , but I think it doesnt matter what level i am studing , i just need to solve the problem. Use calculus or whatever .
     
  9. Mar 21, 2006 #8

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    I've looked in six college textbooks, and I can't find any reference to that peculiar formula. Sorry, but I'm done here :frown:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Magnetic Induction Problem
  1. Magnetic Induction (Replies: 9)

Loading...