# Few students use the Voltage-Resistance-Current (VRI) model of a series circuit

Electricity and Magnetism

Misconception

Only a few students employ a model of a series circuit where an agent, measured in volts, drives an electric current around the circuit. The current's magnitude is also influenced by the circuit's resistance (the VRI model).

### Diagnostic Resources

The following worksheets may help to identify whether students hold this particular misconception.

• Relationship between Current and Voltage and Resistance (11-14)

This resource offers teachers some guidance on how to successfully disentangle the concepts of electric current, voltage and resistance for students.

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• Simple measurements and calculations (14-16)

Introduce a number of circuits where the goal is to find the effective resistance of the circuit. Students need to choose where to put the ammeter and voltmeter, and then transfer their choice and readings to the calculations templates.

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• Measuring resistance with a voltmeter and an ammeter (11-16)

This series of experiments should give students practice in taking a pair of current and potential difference readings for various components so that the resistance of the component can be calculated from V/I = R.

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• Episode 108: Resistance (16-19)

Students likely have some prior exposure to the concept of resistance from pre-16 science courses, so it's effective to build on their existing knowledge. In this initial part, the goal is to establish a quantitative definition for resistance (R = V / I), reinforcing the qualitative understanding that higher resistance results in lower current. Additionally, Ohm's law, distinct from the resistance definition, will be discussed.

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## References

• Dupin, J. J. and Johsua, S. () Conceptions of French pupils concerning electric circuits: Structure and evolution. Journal of Research in Science Teaching, 24 (9), 791-806.

Overcoming student misconceptions about currents and voltages can be difficult, and students can retain inaccurate ideas in the links between these are not discussed fully. This paper shows how some of the misconceptions can be tackled successfully while outlining those that are more difficult to resolve.

Paper digest

• Millar, R. and King, T. () Students’ understanding of voltage in simple series electric circuits. International Journal of Science Education, 15 (3), 339-349.

• Liégeois, L., Chasseigne, G., Papin, S. and Mullet, E. () Improving high school students' understanding of potential difference in simple electric circuits. International Journal of Science Education, 25 (9) 1129-1145.