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Question
In the following diagram an arrow shows the motion of the coil towards the bar magnet.
(1) State in which direction the current flows, A to B or B to A?
(2) Name the law used to come to the conclusion.
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Solution
(1) The direction of current in the coil is from A to B.
(2) The law used is the Lenz’s law of electromagnetic induction.
The coil is moving towards the North Pole of the magnet. Due to this, there is a change in magnetic flux in the coil. Now, the direction of induced e.m.f. (induced current) is such that it opposes this change in flux. Hence, the right end of the coil should also behave as North Pole. Hence, the current will be in the anti-clockwise direction, i.e., from A to B.
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