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Physics/Compass Needle Polarity


LAW wrote at 2010-09-06 05:42:11
No, no, no!  The earth's (Magnetic) North pole was NOT named after the north pole of a magnet!!!  It's the OTHER WAY AROUND!  

The earth's Magnetic North is a geographical location (which varies somewhat from True North  -the location of the actual North Pole).  Because a freely-suspended magnet points to this location, it was then called the 'North-Seeking' pole of the magnet.  Over time, we no longer use 'seeking' to describe that end of a magnet, and we call it its 'north pole', and this is used to describe its magnetic polarity.  Since 'unlike poles attract', to attract the north (seeking) pole of a magnet, the earth's Magnetic North Pole (the location) must have a south magnetic polarity.

Outsidethebox wrote at 2012-10-24 16:17:36
I believe the real answer could be either way, seeing as how the names give to the magnetic forces involved, North and South,  are human made concepts. The reality is that they are just opposites that point to their respective, opposite locations on the globe. Both answers are correct.

awaygood wrote at 2014-03-08 08:23:01
'Magnetic North' is so-called to distinguish it from 'True North'.  It does not relate to its magnetic polarity, nor was it 'named after the north pole of a magnet' (the magnet was named after the direction it which it points!).

A compass's north pole is attracted towards Magnetic North, so that location must be a south pole.

awaygood wrote at 2015-05-23 14:22:03
The answer is straightforward. 'Magnetic North' is a location, so-called to distinguish it from Geographic North. Its name has got nothing to do with its magnetic polarity.

The magnetic polarity of a magnet's (or compass needle's) poles are named after the direction in which they point (not, as suggested by the original answer, the other way around!). This means that the polarity of 'Magnetic North' must be a south pole.


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James J. Kovalcin


I am teaching or have taught AP physics B and C [calculus based mechanics & electricity and magnetism] as well as Lab Physics for college bound students. I have a BS in Physics from the University of Pittsburgh and a Master of Arts in Teaching from same. I have been teaching physics for 34 years. I am constantly updating my skills and have a particular interest in modern physics topics.

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