Thrown for a Current Loop: Torque and Energy in a Magnetic Field
A loop carrying current.Copyright 2008 Trixt, Wikimedia Commons http://commons.wikimedia.org/wiki/File:Loop_antenna.jpg
Students begin to focus on the torque associated with a current carrying loop in a magnetic field. They solve example problems as a class and use diagrams to visualize the vector product. In addition, students learn to calculate the energy of this loop in the magnetic field. Through the associated activity, "Get Your Motor Running," students explore a physical model to gain empirical data and compare it to their calculated data. A homework assignment is also provided as a means of student assessment.
Biomedical engineers must consider not only the force resulting from a charged particle in a magnetic field but also, a current traveling through a magnetic field. During resonance and relaxation, engineers can determine the frequency of the oscillating magnetic field based on a small current in the receiver coil of the MRI machine. In the homework assessment section of this lesson, students will have to determine the magnitude and direction of the torque on a current loop due to the magnetic field.
After this lesson students should be able to:
- Describe the actions of a current loop in a magnetic field.
- Draw and fully label a diagram of current acting through a loop.
- Calculate the torque on a current loop due to a magnetic field.