Final answer:
The percentage change in resistance of the tungsten filament due to thermal expansion is 1100%.
Step-by-step explanation:
The question involves the change in resistance of a tungsten filament in a lightbulb due to thermal expansion. The resistance of the filament increases as it gets hotter. To calculate the percentage change in resistance, we can use the formula:
Percentage Change in Resistance = (Rexpansion - R0) / R0 * 100%
Substituting the given values, we have:
Percentage Change in Resistance = (140Ω - 12Ω) / 12Ω * 100% = 1100%