Slinkies as Solenoids
A metal slinky functions as a solenoid in this activity.Copyright 2008 Megan Brock, Free Images, Getty Images http://www.sxc.hu/photo/61986
Students use a classic children's toy, a metal slinky, to mimic and understand the magnetic field generated in MRI machines. The metal slinky mimics the magnetic field of a solenoid, which forms the basis for the magnet in MRI machines. Students run current through the slinky and use computer and calculator software to explore the magnetic field created by the slinky.
Solenoids form the basis for the magnet of MRI machines, an imaging tool designed by engineers. Exploring the properties of this solenoid helps students understand the MRI machine. In handout questions 5 and 6, students are asked to apply what they have learned during the experiment to design a safe environment around MRI machines.
After this activity, students should be able to:
- Determine the relationship between magnetic field and the number of turns per meter in a solenoid.
- Explain how the field varies inside and outside a solenoid.
- Design an experiment that measures the value of μ0, the permeability constant.