Names _______________________________________________________ Basic Magnetism
1) A permanent magnet is a device that retains a magnetic field without need for a power source.
Though many of us have experienced the effects of magnetism from a permanent magnet, very
few people can describe what causes permanent magnetism. Explain the cause of permanent
magnetism, in your own words.
2) If we were to trace the magnetic field lines from this bar magnet, what would they appear like?
3) Magnetic poles are designated by two labels: "North" and "South". How are these labels defined?
Explain how we can experimentally determine which ends of a magnet are "North" and "South",
respectively?
4) Devise a method of identifying the poles of a magnet that is too large and heavy to move.
5) What happens to the magnetic field lines emanating from a magnet, when an unmagnetized
piece of iron is placed near it?
6) Describe the so-called "domain theory" of magnetism, as it applies to permanent magnets.
7) Define the following terms:
• Ferromagnetic
• Paramagnetic
• Piamagnetic
8) A mechanic visits you one day, carrying a large wrench. She says the wrench became
magnetized after setting it near a large magnet. Now the wrench has become an annoyance,
attracting all the other tools in her toolbox toward it. Suggest a way to demagnetize the wrench for
her?
9) Many electronics are very sensitive to magnetic fields, and need to be shielded from magnetical
fields. Suggest a way to keep stray magnetic fields away from this instrument?
10) Explain the difference between the geograhphical North pole and the Earth’s magnetic North
pole.
11) Explain magnetic induction
12) Draw field lines around 2 bar magnets placed end-to-end with the north end of the first
magnet placed near the south end of the second magnet.
13) Draw field lines around 2 bar magnets placed end-to-end with the north end of the first
magnet placed near the north end of the second magnet.
14) What are some similarities between electric charges and magnetic charges?
15) What are some differences between electric charges and magnetic charges?
16) What is the biggest difference between a generator and a motor?
17) Explain how transformers work and the two types of transformers.
18) Which one of the following statements concerning permanent magnets is false?
A) The north pole of a permanent magnet is attracted to a south pole.
B) All permanent magnets are surrounded by a magnetic field.
C) The direction of a magnetic field is indicated by the north pole of a compass.
D) Magnetic field lines outside a permanent magnet originate from the north pole and
end on the south pole.
E) When a permanent magnet is cut in half, one piece will be a north pole and one piece
will be a south pole.
19) Explain how a nonmagnetic iron nail can be made into an electromagnet?
20) How does a compass work?