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Question
For the coil in the diagram below, when the switch is pressed:
(a) what is the polarity of end A?
(b) which way will the compass point then?
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Solution
When the switch is pressed,
(a) the current will flow in the clockwise direction at end A; therefore, this end will behave like the south pole.
(b) The other end of the coil will behave like the north pole, and because of the repulsive force at the north pole, the compass (or point of the compass) will move away from the coil.
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