1
$\begingroup$

magnetic field lines are from north pole to south pole outside a bar magnet but its direction is from south pole to north pole inside it. Why and what causes it?

$\endgroup$

marked as duplicate by John Rennie, Qmechanic May 1 '18 at 5:42

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 1
    $\begingroup$ Possible duplicate of What is the direction of magnetic lines of force inside a bar magnet? $\endgroup$ – John Rennie May 1 '18 at 5:25
  • 1
    $\begingroup$ @JohnRennie you are pointing as duplicate to a question closed for "not enough research". If this is closed it will be a closed question pointing to a closed question , a bit off putting, if the objective of the site is as a reference base for future searches. Somebody not familiar with SE will tend to ignore closed questions $\endgroup$ – anna v May 1 '18 at 5:45
1
$\begingroup$

you can understand this more easily if you have a look at the magnetic field lines surrounding an electromagnet coil. each line loops around the coil in an unbroken path and the direction of the field is consistent along the entire length of every loop. these characteristics of magnetic field lines are captured in Maxwell's equations.

if the field lines were not loops- if, instead, all the field lines pointed from the north pole to the south pole inside the magnet as well as outside- this would mean that the magnetic poles in this case were monopoles, which as far as has been determined to date, do not exist in the real world except as mathematical constructs in certain unified field theories.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.