Circular Wire Loop

When the applet has loaded, Start.


A cross section of a circular wire loop carrying an unknown current is shown above.   The arrows represent the direction of the magnetic field.  The color of the arrows represents the magnitude of the field with magnitude increasing as the colour changes from blue to green to red to black. A dragable compass is also in the field.

You can:

  • double-click in the animation to add magnetic field lines,
  • click-drag the compass to reposition it,
  • click-drag the center of the loop to reposition it, and
  • click-drag the top or bottom of the loop to change its size (radius). 


Does current flow out of the red end or the blue end?  Explain how you determined your answer.

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