North and South Poles Always Come in Pairs
North and south poles always occur in pairs. Attempts to separate them result in more pairs of poles. If we continue to split the magnet, we will eventually get down to an iron atom with a north pole and a south pole—these, too, cannot be separated.
Source
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"OpenStax College, College Physics. November 21, 2012."
http://cnx.org/content/m42366/latest/?collection=col11406/1.7
OpenStax CNX
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