a. \(R=\dfrac{U^2}{P}=\dfrac{110^2}{25}=484\left(\Omega\right)\)
b. \(A=Pt=25.4=100\)(Wh) = 360 000 (J)
a) \(P=\dfrac{U^2}{R}\Rightarrow R=\dfrac{U^2}{P}=\dfrac{10^2}{25}=4\left(\Omega\right)\)
b) \(t=4h=14400\left(s\right)\)
\(A=P.t=25.14400=360000\left(J\right)=100\left(Wh\right)\)