12.4 12.3 Factors affecting Measuring current Might help: (Something that resistance of a conductor and inferring could be acted out?) Carrying resistance not stacks of parcels in a crowded – The greater the resistivity measuring corridor. Things get knocked off or length of wire, the resistance directly the stacks by collisions greater the resistance To derive More gets knocked off the The greater the area rule, longer the corridor (length), and area, the lower need to remind the narrower the corridor, the the resistance students that higher the frequency of doubling the collisions diameter quadruples the area Remembering relationship 12.5 12.4 For resistors in series: Relating circuit to Might help: Sweet model current the same circuit diagram anywhere in a series used up’ ‘current circuit. Current depends misunderstanding on the total value of the resistance 12.6.1 12.5 For resistors in series: Relating circuit to – potential difference is circuit diagram sum of potential differences across each resistor As V = IR, the combined resistance of resistors in series = sum of individual resistances Section Activity Key teaching Sources of What models or analogies points/what do I want difficulty? are being used or might help students to learn from here? activity and related text?
12.4 12.3 Factors affecting resistance of a conductor The greater the resistivity or length of wire, the greater the resistance The greater the area, the lower the resistance Measuring current and inferring resistance – not measuring resistance directly To derive area rule, need to remind students that doubling the diameter quadruples the area Remembering relationship Might help: (Something that could be acted out?) Carrying stacks of parcels in a crowded corridor. Things get knocked off the stacks by collisions More gets knocked off the longer the corridor (length), and the narrower the corridor, the higher the frequency of collisions 12.5 12.4 For resistors in series: current the same anywhere in a series circuit. Current depends on the total value of the resistance Relating circuit to circuit diagram ‘current used up’ misunderstanding Might help: Sweet model 12.6.1 12.5 For resistors in series: potential difference is sum of potential differences across each resistor As V = IR, the combined resistance of resistors in series = sum of individual resistances Relating circuit to circuit diagram – Section Activity Key teaching points/what do I want students to learn from activity and related text? Sources of difficulty? What models or analogies are being used or might help here?
SS10_AIE_Final.docx