the eeps Data Zoo
curator:Tim Erickson
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 Electromagnet 1

We made an electromagnet—not a particularly strong one—by winding some 32-gauge magnet wire 100 times around some plastic pipe, and then put a steel bolt inside the pipe. Then we suspended that setup over a small permament magnet that was strapped to a Vernier force probe. The two magnets attracted one another, so our reading is the (upward) pull on the probe.

We zeroed the probe before bringing the electromagnet into the picture (but the zeroing compensates for the weight of the permament magnet).

height is the distance between the electromagnet and the permanent magnet in centimeters.
current is the current through the electromagnet in Amperes.
force is the force in Newtons, the pull on the permanent magnet.

How does the force depend on the current?

If you fit a line to the force-current data, what do the slope and intercept mean?

Why is there a force reading when the current is zero?

How does the force depend on the distance? (and how does this relate to the other magnetism exhibits in the zoo?)

(data by Bryan Cooley, Jan 2003)

 height current force 0.9 0 0.27 0.9 0.49 0.294 0.9 0.75 0.311 0.9 1.00 0.333 0.9 1.25 0.347 0.6 0 0.61 0.6 0.50 0.655 0.6 0.75 0.686 0.6 1.00 0.72 0.6 1.25 0.756 0.3 0 1.048 0.3 0.5 1.127 0.3 0.75 1.177 0.3 1.00 1.23 0.3 1.25 1.292 0.3 1.50 1.36

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 ©2003 eeps media 866.341.3377 or Last updated 23 January 2003 supported by NSF award DMI-0216656