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Homework Help: Square Loop Of Wire True or False

  1. Mar 11, 2010 #1
    1. The problem statement, all variables and given/known data
    A square loop of wire with a small resistance is moved with constant speed from a field free region into a region of uniform B field (B is constant in time) and then back into a field free region to the right. The self inductance of the loop is negligible.

    http://capa-new.colorado.edu/msuphysicslib/Graphics/Gtype64/prob24_loop1.gif

    A) Upon entering the field, a clockwise current flows in the loop.
    B) While the loop is entirely in the field, the emf in the loop is zero.
    C) Upon leaving the field, a clockwise current flows in the loop.
    D) When entering the field the coil experiences a magnetic force to the right.
    E) When leaving the field the coil experiences a magnetic force to the left.

    2. Relevant equations
    k so i assume we use the right hand rule for all of these.


    3. The attempt at a solution
    The only one that I know for sure to be right is B. Other then that I am a little confused. if you can just give me some hints that would help greatly
     
  2. jcsd
  3. Mar 11, 2010 #2
    Please someone help me
     
  4. Mar 11, 2010 #3

    marcusl

    User Avatar
    Science Advisor
    Gold Member

    Hint: Look up Lenz's law in your book. It states that the current will flow in a direction to oppose the applied field. (You'll need your right-hand rule to figure it out). Lenz's law will also tell you the answer to D, E if you think about it.
     
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