Your company's baking appliance is controlled by an embedded microprocessor. The microprocessor must receive an input value related to the temperature before it signals the heating element to apply additional heat. The computer only accepts electrical signals, and in particular, digital values as input. Therefore, we need to produce an electrical signal for the computer that changes as the temperature changes. We produce the signal with a circuit that contains a thermistor.
Thermistors give analog, or continuously varying values.
We must convert the analog signal to a digital one so it can be read by the computer. In our experiment, a thermistor converts the physical variable, temperature, to resistance. You must build a voltage divider circuit to produce a voltage signal that will change as resistance and temperature varies. The reason is that the voltage wouldn't vary across the thermistor if it isn't in series with another resistor. Without the other resistor, the thermistor resistance variation would change the current, but not the voltage.