A technician joins in series a 50 cm long copper wire and a 50 cm long nichrome wire, each of uniform diameter 1.0 mm. The resistivity of copper at 20 °C is 1.7×10−8Ωm and that of nichrome is 1.1×10−6Ωm. The temperature coefficient of resistance per degree Celsius is 0.004/∘C for copper and 0.0004/∘C for nichrome.
(i) Calculate the resistance of each wire at 20 °C.
(ii) Find the total resistance of the series combination at 20 °C.
(iii) The temperature of the entire series combination rises uniformly to 50 °C. Determine the new resistance of each wire and the new total resistance at this temperature.
(iv) Which wire contributes more to the change in total resistance with temperature? Justify your answer with suitable numerical comparison.