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Question
Use Lenz’s law to determine the direction of induced current in the situation described by the figure.
A circular loop being deformed into a narrow straight wire.
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Solution
According to Lenz’s law, the direction of the induced emf is such that it tends to produce a current that opposes the change in the magnetic flux that produced it.
The area and, by extension, the magnetic flux associated with a deformed circular loop are smaller than those of a straight wire. Consequently, the magnetic field is pointing upwards because an induced current is set up in an anticlockwise manner.
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