A 1.50m cylindrical rod of diameter 0.450m is connected to a power supply that maintains a constant potential difference of 13.0V across its ends, while an ammeter measures the current through it. You observe that at room temperature (20.0 degrees C) the ammeter reads 18.4A, while at 92.0 degrees C it reads 17.0A. You can ignore any thermal expansion of the rod.
A) Find the resistivity and for the material of the rod at 20 degrees C
B) Find the temperature coefficient of resistivity at 20 degrees C for the material of the rod.