An appliance rated 440 W, 220V is connected across 220V supply.
Calculate the resistance of the appliance.
Topic: Current, resistance and circuits
Answer
Given: P = 440 W, V = 220 V
From P = V² ÷ R: R = V² ÷ P = (220)² ÷ 440 = 48 400 ÷ 440 = 110 Ω
Resistance of the appliance = 110 Ω
Either route works. R = V²/P uses the rating directly; or take the current from part (a) and use R = V/I = 220 ÷ 2 = 110 Ω. Both give 110 Ω, and doing it the second way is a free check on your first answer.
Square the voltage, do not just double it: 220² is 48 400, not 440. That slip gives R = 1 Ω, which for a mains appliance would be dangerously low.
Note that a HIGHER power rating means a LOWER resistance at the same voltage. A 1000 W heater has less resistance than a 60 W bulb — which is why it draws more current and gets hotter.