Examine the dependence of resistivity and resistance of a wire on temperature and how it affects the potential difference across the terminals of the wire.
A current of 60 mA flows through a wire of length L= 1.65 m long and diameter of d=1.1 mm at a temperature of T0= 20 °C; the wire's resistivity at this temperature is ρ0= 5.33×10-8 Ω · m. The coefficient of resistivity of the material is α= 4.6×10-3/C
What is the resistance of the wire at 20 °C?
What is the potential difference across the ends of this wire at 20 °C in milli-volts (mV) ?
If the wire temperature increases to 106 C°, what potential difference (in mV) across its ends is now required to produce a current of 60 mA?