Addressing students’ difficulties with Faraday’s law: A guided problem solving approach

In traditional teaching, the fundamental concepts of electromagnetic induction are usually quickly analyzed, spending most of the time solving problems in a more or less rote manner. However, physics education research has shown that the fundamental concepts of the electromagnetic induction theory are barely understood by students. This article proposes an interactive teaching sequence introducing the topic of electromagnetic induction. The sequence has been designed based on contributions from physics education research. Particular attention is paid to the relationship between experimental findings (macroscopic level) and theoretical interpretation (microscopic level). An example of the activities that have been designed will also be presented, describing the implementation context and the corresponding findings. Since implementing the sequence, a considerable number of students have a more satisfactory grasp of the electromagnetic induction explicative model. However, difficulties are manifested in aspects that require a multilevel explanation, referring to deep structures where the system description is better defined.

Figure 1

The percentages of correct answers are shown in the experimental pretest (E-Pre) and post-test (E-Post) and in the comparison groups’ post-test (C-Post).

Figure 2

The average percentage of students expressing each of the incorrect answer categories. For example, difficulty B.1 is relevant to all five questions and the percentage of students expressing this difficulty averaged over all five questions is shown. Ideally, all the bars would be at 0% after instruction, indicating that students expressed none of the difficulties.

Figure 3

Experimental setup in the laboratory of activity A.7.

Figure 4

Experimental setup in the laboratory of activity A.19.

Figure 5

The small circle represents the conducting ring inside the solenoid.

Figure 6

The switch $S$ of the circuit with a battery is closing.

Figure 7

A magnet is moving towards a conducting coil which is at rest from our observation.

Figure 8

The coil is rotating in a stationary magnetic field.

Figure 9

The coil is coming out of a stationary magnetic field.

Figure 10

Faraday’s generator.