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Magnetic Field Activities
for the High School Classroom
The following unit is designed to acquaint the student with the magnetic field.
The assumed average student has some familiarity with the uniform gravitational
field of classical Newtonian dynamics and kinematics lessons. This is not required
however. The unit is meant to introduce the idea of a field through investigations
of magnetic fields as produced by various common magnetic materials and direct
currents. The difference between a magnetic field and a gravitational field is
that a gravitational field, in the experience of a student, always points downward
and is always of the same strength (9.8 m/s2). Magnetic fields are not limited to
one direction or strength, in the student's experience. That is, all students are
assumed to have noticed that some magnets are stronger than others. Further, all
students will know, by the mid-point of this unit, that magnetic fields are inherently
loop shaped. One important similarity does exist between the magnetic field of the
earth and the gravitational field of the earth: both are mysteriously produced by the
same object. Thus, these two fields are easily confused in the mind of the student,
and are subject to 'common sense' interpretations that may be at odds with scientific
explanation. The 'common sense' interpretations can be hard to modify. Indeed,
students are likely to speak as if all magnetic interactions are attractive (e.g.,
'the magnetic personality') even though they also know from experience that it is
hard to force opposite poles of different magnets together.
In general terms, the student will gain an appreciation for the vector nature of
fields, the ubiquity of field sources in the environment, and the ability to
visualize such fields as 3-dimensional entities.
Specific Learning Outcomes:
- The student will learn that a magnetic field is a real entity with real effects.
- The student will learn that moving charges or currents are needed to produce and
detect a magnetic field.
- The student will be able to explain the root cause of the apparently "permanent
magnetism" of materials such as iron, cobalt, and nickel.
- The student will learn to construct a vector field description of how a magnet
affects the space around it.
- The student will be able to construct a field diagram based on a series of
- The student will design and construct an apparatus which allows the detection of
magnetic field direction at the location of the instrument.
- The student will design, execute, interpret and report on a series of experiments
leading to a coherent qualitative understanding of magnetic fields.
- The student will understand the direction and magnitude content of vector
- The teacher will use a Socratic approach and guided learning methods.
Magnetoreceptors in animals
Magnetism and bacteria
Magnetism and newts
Overview of animals and magnetism, especially migration
Lobsters, turtles, and mollusks
- Rainbow trout:
Walker, Michael M., Carol E. Diebel, Cordula V. Haugh, Patricia M. Pankhurst, and
John C. Montgomery, 1997.
"Structure and function of the vertebrate magnetic sense," Nature 390, 371.
This article describes how rainbow trout can sense and respond to magnetic
fields. It tells where in the nose the trouts' magnetoreceptors are located and
how they are connected to the brain. Perhaps this sensory system enables trout to
navigate over long distances using Earth's magnetic field for orientation. (See also
- Another magnetometer recipe
- Variations in magnetic field of the earth:
- Magnetizing Objects:
Lesson Development/Writing: Ed Eckel
and Matthew Friel
Web Design: Theresa Valentine
Last Updated: 8/25/2000
Above is background material for archival reference only.