A resistor has a resistance of 10 Ω at 20 °C. Its temperature coefficient of resistance is 0.004 °C⁻¹. The resistor is connected across a 24 V dc supply.
(i) Find its resistance when its temperature rises uniformly to 80 °C.
(ii) Calculate the power dissipated at 20 °C.
(iii) Calculate the power dissipated at 80 °C.
(iv) Determine the percentage change in power between the two temperatures.