An appliance rated 440 W, 220V is connected across 220V supply.
(a) Calculate the maximum current that the appliance can draw.
(b) Calculate the resistance of the appliance.
(a) Maximum current drawn = I = WV\dfrac{\text{W}}{\text{V}}VW = 440220\dfrac{440}{220}220440 = 2A
(b) Resistance of the appliance = R = WI2\dfrac{\text{W}}{\text{I}^2}I2W = 4404\dfrac{440}{4}4440 = 110Ω
