Sample 1Medium
A diagram shows a bar magnet held horizontally with its north pole facing one face of a stationary closed coil. The magnet is pushed towards the coil. What is the direction of the induced current in the coil, as seen from the magnet's side?
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The answer is A.
By Lenz's law the induced current opposes the approach, so the near face of the coil becomes a north pole. A current that looks anticlockwise from that side makes a north face.
- B.
A clockwise current seen from the magnet makes a south face, which would attract the magnet and aid the change.
- C.
The flux through the coil changes as the magnet moves, so an emf is induced even though the coil is still.
- D.
The current does not reverse while the magnet keeps approaching.
NCERT: Class 12 Physics, Chapter 6