Permanent Magnets & Fields
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Using a plastic box filled with iron filings, take your magnets
and examine their interactions. Recall your earlier experiments
with charged tape and straws.
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Q1: How
are the faces of these magnets magnetized? Sketch a magnet, indicating
where the field is strongest and weakest, where it changes direction
and so forth. The iron filings in the clear box together with the
other magnet will help characterize the fields of these magnets. |
Use the iron filings in the clear box to examine the field between
two magnets.
Q2: Draw
the observed field between two magnets in two different configurations.
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Assemble the magnetic field test stand as shown, using a paper
clip, string or a rubber band and tape. Suspend the clip as shown.
Q3: Draw
a free body diagram for the
steel paper clip.
Q4: If
the paper clip shown has a mass of 1.45g, what must be the minimum
upward magnetic force upon it?
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Test the effect of different materials upon the magnetic field
by placing a sample within the gap and observing any effects on
the clip. Try paper, cloth, plastic, coins, other clips.
Q5: Which
substances do and do not effect the field and how?
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Construct a chain of paper clips as shown. What is the maximum
number of clips you can suspend?
Q6: How
can you use a second magnet to increase this number (sketch this)?
Carefully free the topmost clip in your chain from the magnet,
and gradually increase the spacing between the top clip and the
magnet.
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Q7: Starting
from contact, slowly remove the magnet to a distance of 1 cm. Describe
what you observe.
Q8: With
a drawing explain this phenomenon in terms of lines of magnetic
field.
Q9: How
many kinds of magnetism must exist? Justify your answer by referring
to your observations of magnetic interactions.
Q10: How
do these fields compare to the electric fields you have studied?
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