Câu hỏi 9

Từ đồ thị ta có \(\frac{T}{2} + \frac{T}{{12}} = {70.10^{ - 3}}s =  > T = 0,12s =  > \omega  = \frac{{50\pi }}{3}\)

\(\left\{ \begin{array}{l}{\varphi _u} =  - \frac{{2\pi }}{3}\\{U_0} = 100V\end{array} \right. =  > \left\{ \begin{array}{l}{\varphi _i} = {\varphi _u} + \frac{\pi }{2} =  - \frac{\pi }{6}\\{I_0} = \frac{{{U_0}}}{{{Z_C}}} = \frac{{100}}{{50}} = 2A\end{array} \right. =  > i = 2\cos \left( {\frac{{50\pi t}}{3} - \frac{\pi }{6}} \right)(A)\)