Unit: Electricity and Magnetism

ATLAS Experiment, LHC, CERN

If two bar magnets are oriented so that their opposite poles face one another and slowly moved together, they will 1.repel since the two Souths are the same type of pole. 2.one will rotate 180° and they will attract 3.each rotates 90° so that they are aligned next to each other (i.e., North to the other’s South) N SS N

A long, thin bar magnet has a north pole at one end and a south pole at the other. If you break it in half, the two new ends will 1.attract 2.repel 3.neither attract nor repel N S

The steel in an ordinary refrigerator 1.has no magnetic structure in it 2.has magnetic domains, oriented semi- randomly 3.has one north pole and one south pole 4.has several north poles and several south poles

When a bar- or button-shaped permanent magnet is first formed out of molten ingredients, it has 1.no magnetic poles on its ends 2.north magnetic poles on both of its ends 3.south magnetic poles on both of its ends 4.a north pole and a south pole at opposite ends

Questions: E11.3: If you bring two magnetic compasses nearby, they will soon begin attracting one another. Why don’t they repel? E11.5: If you hold a permanent magnet the wrong way in an extremely strong magnetic field, its magnetization will be permanently reversed. What happens to the magnetic domains inside the permanent magnet during this process? Current is flowing through a coil as shown. Which side of the coil would be attracted to the North pole of a bar magnet? Current