2.12 Describe the qualitative variation of resistance of LDRs with illumination and of thermistors with temperature

LDRs are light dependent resistors. This means that the brighter the light, the less resistance there is. (so the dimmer the light, the more resistance.)

Figure 1 - Circuit symbol for LDR

Thermistors are temperature dependent resistors.This means that the higher the temperature, the lower resistance there is. When it is cold, the resistance is high.

Figure 2 - Circuit symbol for thermistor