Abstract
We investigate student confusion of concepts of electric and magnetic force. At various times during a traditional university-level course, we administered a series of simple questions about the direction of force on a charged particle moving through either an electric or a magnetic field. We find that after electric force instruction but before magnetic force instruction most students answer electric force questions correctly, and we replicate well-known results that many students incorrectly answer that magnetic forces are in the same direction as the magnetic field. After magnetic force instruction, most students answer magnetic force questions correctly, but surprisingly many students incorrectly answer that electric forces are perpendicular to electric fields, as would happen if a student confused electric forces with magnetic forces. As a further indication of interference between electric and magnetic concepts, we also find that students' responses depend on whether electric or magnetic force questions are posed first, and this effect depends on whether electric or magnetic force was most recently taught.
Highlights
Electricity and magnetism are very similar and closely related phenomena
A second method that can be employed to determine the extent to which students are confusing concepts of electricity and magnetism is to examine the effects of question order on student answering; will there be a difference in student answering if the electric force questions are posed before the magnetic force questions as opposed to after? Differing answer distributions would be an indication of the phenomenon ‘‘cognitive priming,’’ in which exposure to one stimulus will influence the response to a subsequent stimulus
The most important and surprising finding of this study is that, directly after instruction about magnetism, many students answer that the direction of the force on a charged particle moving through an electric field is perpendicular to the electric field, presumably by employing the same right-hand rule that was learned for magnetic forces
Summary
Electricity and magnetism are very similar and closely related phenomena. There is evidence suggesting that these simple similarities may be driving student difficulties in distinguishing between the phenomena of electricity and magnetism. Many students (incorrectly) believe that magnetic poles carry electrostatic charges [1,2] or that magnetic fields originate from stationary charged particles [2] Some consequences of this confusion are that students confuse electric and magnetic fields [2,3] and are inclined to (incorrectly) answer that the force experienced by a moving charged particle is directed toward a magnetic pole [4,5,6,7] or is in the direction of the magnetic field lines [5,6,7,8,9,10,11]. The studies discussed above highlight the fact that many students use the concepts and representations learned during instruction in electricity (which typically occurs prior to magnetism) to answer questions about magnetism.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
