What is the current passing through the bulb marked with "220V 40W" in normal operation? What is the resistance in normal lighting
"220 V 40 W" means that the rated power of the bulb is 40 W, the rated voltage is 220 V, the current in normal operation is: I = P / u = 40 / 220 = 0.18 (a) the resistance of normal lighting: r = u ^ 2 / P = 1210 (Ω)