In a circuit with a thermistor and bulb, what happens to the brightness of the bulb as the temperature increases?

As the temperature increases, the resistance of the thermistor decreases. So the resistance of the whole circuit decreases. Using V=IR, the PD remains constant but resistance has decreased, so current must increase. Using V=IR in just the bulb, the resistance is unchanged, the current has increased so the PD increases. The bulb gets brighter