The tungsten filament of light bulb has a 0.100 mm diameter. The filament has a resistance of 0.20 Ω at a temperature of . Find the length of the filament. Use a value of Ω⋅m for the resistivity of tungsten at .
A heater is being designed that uses a coil of 14-gauge (1.63 mm diameter) nichrome wire to dissipate 300 W using a voltage of V. How long should the engineer make the wire if the resistivity of nichrome is 1.5 µΩ⋅m?
The air temperature in a town varied between and on a certain summer day. Find the percentage change in the resistance of an exposed aluminum wire in the town during such a day. Use a value of for the temperature coefficient of resistance of aluminum.