Visualizing Magnetic Field Lines
Students take the concept of etch-a-sketch a step further. Using iron filings, they begin visualizing magnetic field lines. To do so, they use a compass to read the direction of the magnet's magnetic field. Then, as they rotate the filings about the magnet, they observe the behavior of iron filings near the magnet. Finally, students study the behavior of iron filings suspended in mineral oil, which displays the magnetic field in three dimensions.
What exactly is a magnetic field?Copyright 2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved.
MRI machines produce very strong magnetic fields that must be carefully managed in order to protect personnel and patients from excessive polarization as the protons in their bodies align with the polar field. Patients may also possess implants or foreign objects that could interact with the magnetic field. Post-activity assessment questions 4 and 5 focus on the implications of a magnetic field as strong as that of an MRI, while question 6 focuses on those implications with respect to foreign bodies.
After this activity, students should be able to:
- Describe the strength and direction of the magnetic field around a permanent magnet.
- Predict and sketch magnetic field lines.