Moc żarówki podłaczonej do napięcia U1=100V wynosi 100W. Oblicz moc tej żarówki włączonej do napiecia U2=50V.

[latex]P_1=100W[/latex] [latex]U_1=100V[/latex] [latex]R=frac{U_1}{frac{P_1}{U_1}}=frac{{U_1}^2}{P_1}=frac{{100^2}}{100}Omega=frac{1000}{100}=100Omega[/latex] [latex]P_2=U_2cdot I_2=U_2 cdot frac{U_2}{R}=frac{{U_2}^2}{R}=frac{50^2}{100}W=frac{2500}{100}W=25W[/latex]

[latex]P_{1}=100W \ U_{1}=100V \ [/latex] Moc prądu: P = U * I Prawo Ohma: U = R * I [latex]P = U * I \ R = frac{U}{I} \ P = frac{U^2}{R} \ R = frac{10000V}{100W} = 100Omega [/latex] [latex]P_{2}= frac{U_{2}^2}{R} = frac{50V^2}{100Omega} = frac{2500}{100}W = 25W [/latex]