If you were to cut a small permanent bar magnet in half, a) none of these statements is true. b) one piece would be a magnetic north pole and the other piece would be a south pole. c) each piece would in itself be a smaller bar magnet with both north and south poles. d) neither piece would be magnetic.

Explanation:

According to classical physics, a magnetic field always has two associated magnetic poles (north and south), the same happens with magnets. This means that if we break a magnet in half, we will have two magnets, where each new magnet will have a new south pole, and a new north pole. However, the magnetic force of each magnet will be less than that of the original magnet.

This is because for classical physics, naturally, magnetic monopoles can not exist.

Nevertheless,  according to quantum physics, magnetic monopoles do exist, which was predicted by Paul Dirac in 1981. This has led to several experiments and investigations, among which the most recent one so far (year 2014), is the experiment led by a group of scientists from the Amherst College (United States) and the University of Aalto (Finland), that reported having synthesized for the first time in a laboratory a magnet of a single magnetic pole.

answer: b.

explanation:

their crystal patterns have been disrupted by stress