PHYS 1155 Lecture 12: 30454, Kelley, 3-15

Which of the following is true of compasses?

a) a compass is a permanent magnet.

b) a compass has only a north pole.

c) compasses always point toward geographic south

d) compasses are not always magnetized.

A piece of iron rod is wrapped by copper wire. Which of thefollowing is correct?

a) a current in the wire will turn the iron into a magnet
b) if the iron is magnetized, a current will be produced in thewire
c) Both A and B are true
d) Neither A or B is true

Problem 4.
A) Textbook problem 20-11 B) Textbook problem 20-12
C) What is a magnetic domain?
D) How can an unmagnetized chunk of iron be magnetized?
E) Why does dropping a magnetic strip of metal decrease themagnetism of the strip of metal?
F) Why does increasing the temperature of a magnet decrease itsmagnetism?