I=P/U=100w/220v=5A/11=0.4545A。R=U^2/P=(220v)^2/100w=22^2欧=484欧。或：R=U/I=220v/(5A/11)=220x11欧/5=484欧。
R=U^2/P I=P/U
p＝ui＝u�0�5/r . i＝0.45A r＝484Ω
