Day 2: Design and Build a Magnetometer
Lesson Plan


The students will brainstorm and design an instrument to detect magnetic field direction. The design will roughly approximate the design included in this activity.

The students will build a functioning magnetometer, a device for detecting the relative direction of the local magnetic field.

Opening Probing Question/Quiz (short answer):

Is magnetism a material?

Magnetism seems to be caused by a material and experienced by a material. We do not yet see consistent evidence that the magnetic field is itself a material. We can not make a conclusion yet. (And indeed, magnetism is not a material in the usual sense of the word.)


Ask volunteers to brainstorm methods of detecting a magnetic field for direction. List responses on board.

Ask student groups to coordinate/refine design suggestions to workable model.

Through discussion, add the following considerations to the student designs:

Discussion goal: Motivate students to think about what it takes to build a device to measure a physical phenomenon. Ultimately, the student thoughts ought to foreshadow the construction of the magnetometer. This can be achieved by providing questions suggesting the need to use a friction free bar magnet (hanging from a thread) which is not affected by air currents (the bottle). Students may be concerned with the difficulty of noticing small changes. This is a calibration issue that is part of the first activity done with the magnetometer.

At conclusion of discussion/design pahse, hand out student pages for this activity including design directions for a magnetometer. (Magnetometer design adapted from:

Hand out following materials to each group:

Lesson Development/Writing: Ed Eckel
Web Design: Theresa Valentine
Last Updated: 8/15/2000