One particular lightbulb has a 0.22-meter length of the tungsten wire used as its filament. This tungsten wire filament has a resistance of 19 ohms at a temperature of 20°C. The tungsten wire filament has a resistance of 240 ohms when this bulb is operated at a potential difference of
120 volts.
Explain why the resistance of the tungsten wire filament increases when the bulb is being operated compared to the resistance of the filament at
20°C