1. Estimate at what temprature copper will have the same resistivity as tungsten does at 20 degrees celsius.
2. A 100 W light bulb has a resistance of about 12 ohms when cold (20 degrees C) and 140 ohms when hot. Estimate the temperature of the filament when "on" assuming an average temperature coefficient of resistivity = 0.0060 (Celsius)^-1.