PHYS 2212 Module 9.5

Eddy Currents

Recommended Reading

9.5 Eddy Currents

Learning Objectives

By the end of this section, you will be able to:

  • Explain how eddy currents are created in metals
  • Describe situations where eddy currents are beneficial and where they are not helpful

Eddy Currents

These currents are called Eddy currents (like eddy currents in a river or stream). These little eddy currents produce their own magnetic fields that oppose the changing flux. And these induced magnetic fields produce strong drag forces on the falling disk. This process is called magnetic damping or magnetic braking and it used all over the place. One example I can think of is roller coasters. 

And here is a slightly less exciting video showing how magnetic braking works in a desktop demonstration: