Cho mạch điện như hình vẽ bên. Biết uAB=100căn3cos100pit, UAE=50căn6, UEB=100căn2

* Hướng dẫn giải

Đáp án A

Ta có: 

$$\begin{gathered} \left\{\begin{array}{l}{U}_{AB}=50\sqrt{6}\\ U_{RL}=50\sqrt{6}\\ U_C=100\sqrt{2}\end{array}\right.\Rightarrow \left\{\begin{array}{l}{U}_R^2+{\left(U_L-U_C\right)}^2=15000\\ U_R^2+U_L^2=15000\\ U_C=100\sqrt{2}\end{array}\right. \\ \Rightarrow \left\{\begin{array}{l}{U}_C=2U_L=100\sqrt{2}\\ U_C=100\sqrt{2}\end{array}\right.\Rightarrow \left\{\begin{array}{l}{U}_L=50\sqrt{2}\\ U_R=100\\ U_C=100\sqrt{2}\end{array}\right. \\ \Rightarrow U_{RC}=100\sqrt{3} \end{gathered}$$