Thermistor Confusion

I'm in the middle of doing my as- level coursework using a thermistor in a potential divider circuit with a digital multimeter over the fixed resistor. Where as the temperature increases the resistance and voltage across the thermistor decreases.

However when trying to explain why this pattern occurs I've really confused myself. As I'm not sure exactly why the resistance and voltage does decrease across the thermistor?

Also when I have done my graph showing voltage against temperature over the fixed resistor, when it comes to explaining why this trend happens do I explain referring to the thermistor or to the resistor.

I'm really confused so if anyone could help I would really appreciate me

Reply 1

teachercol

ntc thermistors decrease in resistance as they get hot. (they are the most common sort)

The simple explanation is that they are made from semiconductor material. When heated bonds break and electrons (and holes) become available for conduction ie it becomes a better conductor and its resistance drops.

In a potential divider, the PD across each component is proportional to the resistance. If R drops, V drops.