An example of an alternative conception:
It is common for learners to think that as electrivity passes around a series circuit, the current drops at each resistive component. This has been found to be an idea quite resistant to change – so that even when the constant level of current at different points in a ciruit has been demonstrated, and acknowledged by learners, they are often later found to retain the alternative conception (and may indeed misremember the demonstration as showing what they had expected to happen!)
It has been argued that learners commonly think about such a circuit in terms of a sequence of different 'distinct 'events' occurring in different parts of the circuit. (This is not surprising, as people have very limited working memories, and a novice needs to understand any new phenoemna in limited 'learning quanta') but an expert views the overall system and sees how current is determined globally (by considering the p.d. and all the resistances). Learners are also less likely to think about the circuit in terms of an electric field that is propagated throughout the whole cicuit; nor to apreciate the relevance of conservation of charge (i.e., Kirchoff's first law).
(In which direction around a d.c. circuit the current is thought to drop may depend on whether a learner thinks in terms of conventional current or electron flow.)
[Please be aware that a word may have different nuances, or even a different meaning, according to context.]« Back to Index
