A heater element has a resistance of 20 Ω. The current through it can be adjusted with a variable power supply.
(i) Calculate the power dissipated in the element when the current is (a) 1.0 A, (b) 2.0 A, and (c) 3.0 A.
(ii) On graph paper, plot the power values obtained in part (i) on the y-axis against the corresponding current values on the x-axis.
(iii) From the plotted points, state whether the power–current relationship appears linear or non-linear and write the mathematical relationship you expect between P and I for a fixed resistance.
(iv) Using your graph, estimate the current required for the heater to consume 200 W of power.