Many students see circuit behaviour as a sequence of causes and effects, rather than seeing the whole circuit as an interacting system
Misconception
Students frequently provide predictions based on sequential reasoning rather than viewing the entire circuit as an interacting system. For example, they might believe that changes only impact components downstream of the alteration point or that modifying a resistor's value affects only the current or potential difference across that specific resistor.
Diagnostic Resources
The following worksheets may help to identify whether students hold this particular misconception.
For more information, see the University of York EPSE website.
These questions probe the idea that a change at any point in a series circuit alters the current in the same way everywhere, and not just 'after' it (which would indicate a sequential model of circuit behaviour).
EPSE Voltage, Resistance and Current Q23Resources to Address This

The Electrical Flow  All Together Now! (1416)
This resource discusses some of the teaching and learning issues around the idea that circuit behaviour is sequential.
See also Thinking about actions to take
View Resource 
Do the electrical charges move Instantly? (1114)
This resource discusses some common pitfalls in younger students' thinking on 'sequential' circuit behaviour.
View Resource 
The resistance sets the current for the whole circuit (511)
Emphasise that when additional resistance is introduced to a circuit in one place, the current is reduced everywhere in the whole circuit. This can be a source of confusion.
View Resource
References
 Küçüközer, H. and Kocakülah, S. () Secondary School Students' Misconceptions about Simple Electric Circuits. Journal of Turkish Science Education.
Bulbs are often used in the teaching of series and parallel circuits, but using these does not always help students understand the concept of conservation of current and the relationship between voltage, current and energy transfer. This paper discusses some of the students’ misconceptions that need to be addressed and suggests using meters more often to analyse circuit behaviour.
Paper digest  Küçüközer, H. and Kocakülah, S. () Effect of Simple Electric Circuits Teaching on Conceptual Change in Grade 9 Physics Course. Journal of Turkish Science Education.
When studying electricity, the most difficult concept for secondary students to understand is that of potential difference or voltage. Students cannot clearly separate it from current or energy and the simple circuits used do not always help. This paper shows that teachers need to describe and model currents and voltages more clearly, using meters to measure instead of relying on concepts such as ‘brightness’.
Paper digest  Lee, Y. and Law, N. () Explorations in promoting conceptual change in electrical concepts via ontological category shift. International Journal of Science Education, 23 (2), 111149.
These four connected studies involving observations of practical work reveal that students are unclear in their pictures of current, voltages and the behaviour of batteries in circuits. It shows that precise language and allowing students to predict and experiment can encourage them to make more accurate qualitative explanations about what is happening in simple circuits.
Paper digest  Cohen, R., Eylon, B. and Ganiel, U. () Potential difference and current in simple electric circuits: A study of students’ concepts. American Journal of Physics, 51 (5), 407412.
 McDermott, L. C. and Shaffer, P. S. () Research as a guide for curriculum development: An example from introductory electricity. Part I: Investigation of student understanding. American Journal of Physics, 60 (11), 9941003.
 Pardhan, H. and Bano, Y. () Science teachers' alternate conceptions about directcurrents. International Journal of Science Education, 23 (3), 301318.
 Millar, R. and King, T. () Students’ understanding of voltage in simple series electric circuits. International Journal of Science Education, 15 (3), 339349.
 Millar, R. and Beh, K. L. () Students’ understanding of voltage in simple parallel electric circuits. International Journal of Science Education, 15 (4), 351361.
 Shipstone, D. () Pupils' understanding of simple electrical circuits. Some implications for instruction. Physics Education, 23 (2), 92.