圖示正弦電流電路中電壓u(t)的初相等于()
A.36.9° B.-36.9° C.-53.1° D.53.1°
圖示正弦電流電路中電壓u(t)的振幅等于()
A.1V B.4V C.10V D.20V
圖示電路的開關(guān)閉合后,電感電流i(t)等于()
A.5e-2tA B.5e-0.5tA C.5(1-e-2t)A D.5(1-e-0.5t)A