Labo Élec
electrical lab simulator
Exercise from the chapter "Power, energy, efficiency"
Level 2 of 5 · Skills: Calculate
An appliance is rated 40 W / 110 V. What is its resistance?
P = 40 W · U = 110 V
Parametric exercise: the values change with every draw; these are one example.
Guided problem in 4 steps: unknown, formula, units, data, result.
P = U²/R → R = U²/P = 110² / 40 = 303 Ω; the rated current is I = P/U = 0.364 A.