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So the inducing magnetic field points upwards since the field travel south to north in a magnet. The inducing magnetic flux also increases as it heads towards the coil. According to Lenz's Law, the direction of the induced current is such that its magnetic field opposes the change in the magnetic flux that created it.

So I say the induced magnetic flux will travels downwards. As a result the induced current, will travel clockwise.

But according to the solution provided by my textbook which is demonstrated below, my reasoning is incorrect: enter image description here

So who is correct? Is there any misconception from my part? Because my reasoning seems valid to me. Please


1 Answer 1


(a) The first line in the table from your textbook is wrong. The flux from the magnet is upwards through the coil and increasing. It is true that the magnetic field lines will curve round and return to the South pole, but most of the lines will go upwards through the coil before curving back downwards and returning outside the coil. [The textbook-writer would have done well to sketch some of the magnet's field lines.]

(b) Clockwise and anticloclockwise (counterclockwise) are ambiguous terms. You have reasoned correctly that the induced current in the coil is clockwise, but this is when the coil is viewed from above. Viewed from below it is anticlockwise. So you need to state from which direction you are viewing. There are exceptions, such as when talking about going round a 'circular' walk, because no-one would consider viewing the walk from underground. At least I don't think they would...

  • $\begingroup$ Hey Mr.Wood cheers for the answer! So the magnetic flux of the magnet travels upwards and according to lenz's law the induced magnetic flux will point downwards to keep the magnetic flux in the coil constant. Hence the induced current, will travel clockwise when viewed from above. To summary, my conclusion is correct? $\endgroup$
    – CountDOOKU
    Commented Aug 14, 2020 at 13:17
  • $\begingroup$ Yes it is! Note that the upward flux is increasing; this is why there is an induced current. [If one goes on moving the magnet upward, so that its South Pole passes through the coil and emerges above it, the magnet's flux through the coil will still be upwards but decreasing in magnitude, so the induced current will now be in the opposite direction. As I said: if in doubt sketch some field lines.] A small point: I recommend not talking about flux "travelling". $\endgroup$ Commented Aug 14, 2020 at 13:29
  • $\begingroup$ Thanks for the guidance! $\endgroup$
    – CountDOOKU
    Commented Aug 15, 2020 at 2:16

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