Physics
The diagram below shows a coil connected to the centre zero galvanometer.
What polarity is induced at point X when
(a) the magnet is moved towards the coil
(b) the magnet is moved away from the coil?
Answer
(a) South pole
Reason — A moving south pole of a magnet near a coil induces a current. The induced current creates a magnetic field opposing the change, following Lenz's law. This leads to the coil's side facing the south pole developing a south pole as well.
(b) North pole
Reason — Moving a magnet's south pole away from a coil induces a current. The induced current creates a magnetic field opposing the change, following Lenz's law. This leads to the coil's side facing the south pole developing a north pole.
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