Whole lesson on resistance theory including questions, pick a pair game and printable cards.
Explain that the resistance is varied as a result of changing the length of resistance wire in a variable resistor.
Use and manipulate the equation: R = V / I.
Calculate the resistance of an ohmic conductor from a voltage-current graph.
Explain the shape of a voltage-current graph for a non-ohmic conductor, such as filament lamp, in terms of changing resistance.