Students will carry out a structured inquiry investigation of Faraday’s Law of Induction, a physical law that states that the bigger the change in the magnetic field, the greater the voltage produced in a conducting coil. Students will observe Faraday’s Law in action, by investigating the question: How does the speed of a magnetic field moving through a copper wire coil affect the amount of electricity (moving charges- current) produced?
Students will be directed through an investigation in which a strong magnet moves quickly through coiled copper wire to generate electricity. In the investigation, a strong ceramic magnet is attached to the top of a matchbox style car and released down an inclined track through a thick coil of copper wire. The resulting voltage is measured. Students will use a multimeter to collect voltage data (in millivolts) as a function of the release position of the magnet. The release position of the magnet on an inclined track will effectively control the speed of the toy car to which it is attached. Therefore, the voltage data will be collected as a function of the speed of the magnet, or as a function of the rate of change in the magnetic field as the car passes through the coil.
Students will create a graph of these data, analyze the data, and present their results and conclusions to the class. Students will also learn about Michael Faraday’s contributions to the understanding of electricity.
Students will further explore induction through participation in online simulations.
Lesson developed through a grant-funded project with Sweet Briar College and Lynchburg College. It was orginally published on STEM4Teachers.org. Lesson description published in Science and Children, October 2013.
Yochum, H., Vinion-Dubiel, A., Granger, J., Lindsay, L., Maass, T., Mayhew, S. (2013). Electromagnetic Induction. Science and Children. 51(2), 63-67.