9.3 Resistance and resistivity

1 define resistance
2 recall and use V = IR
3 sketch the I–V characteristics of a metallic conductor at constant temperature, a semiconductor diode
and a filament lamp
4 explain that the resistance of a filament lamp increases as current increases because its temperature
increases
5 state Ohm’s law
6 recall and use R = ρL /A
7 understand that the resistance of a light-dependent resistor (LDR) decreases as the light intensity
increases
8 understand that the resistance of a thermistor decreases as the temperature increases (it will be
assumed that thermistors have a negative temperature coefficient)