A wire 50.0 m long and 2.00 mm in diameter is connected to a power source with a potential difference of 9.11 V and a current of 36.0 A flows through the wire.
a) What is the resistance R of the wire?
b) What is the resistivity ρ of the wire?
c) What material is the wire made from? (assume the wire is at a temperature of 20 °C)
d) The wire is now stretched so that it becomes twice as long, but the volume of material remains the same. What is its resistance now?