Mạch điện xoay chiều có C thay đổi

A  \({Z_C} = \frac{{\sqrt {{R^2} + Z_L^2} }}{{{Z_L}}}\)

B  \({Z_C} = R + {Z_L}\)

C  \({Z_C} = \frac{{{R^2} + Z_L^2}}{{{Z_L}}}\)

D  \({Z_C} = \frac{{{R^2} + Z_L^2}}{R}\)

A \({U_{RCm{\rm{ax}}}} = \frac{{U\sqrt {{R^2} + Z_C^2} }}{{2R}}\)

B \({U_{RCm{\rm{ax}}}} = \frac{{2U}}{{\sqrt {4{R^2} - Z_L^2} }}\)

C \({U_{RCm{\rm{ax}}}} = \frac{U}{{\sqrt {4{R^2} - Z_C^2} }}\)

D \({U_{RCm{\rm{ax}}}} = \frac{{U\sqrt {{R^2} + Z_C^2} }}{{2{Z_C}}}\)

A \({C_0} = \frac{1}{{{\omega ^2}L}}\)

B \({C_0} = \frac{{{R^2} + Z_C^2}}{{\omega L}}\)

C \({C_0} = \frac{1}{{{{(\omega L)}^2}}}\frac{{{R^2} + Z_C^2}}{{\omega L}}\)

D \({C_0} = \frac{1}{{{{(\omega L)}^2}}}\)

A \({P_{{\rm{max}}}} = \frac{{{U^2}}}{R}\)

B \({P_{{\rm{max}}}} = \frac{{{U^2}}}{{2R}}\)

C \({P_{{\rm{max}}}} = I_0^2R\)

D \({P_{{\rm{max}}}} = \frac{{{U_0}^2}}{{{R^2}}}\)

A  \(U_{Cm{\rm{ax}}}^2 = {U^2} - U_R^2 - U_L^2\)

B

 \(U_{Cm{\rm{ax}}}^2 = {U^2} + U_R^2 + U_L^2\)

C  \(U_{Cm{\rm{ax}}}^2 = \frac{{{U^2}}}{{U_R^2 + U_L^2}}\)

D  \(U_{Cm{\rm{ax}}}^2 = {U^2} + \frac{1}{2}(U_R^2 + U_L^2)\)

A \({Z_C} = \frac{{{Z_L}}}{2}\) thì U_{RC max}

B U_RL không phụ thuộc vào R khi \({Z_C} = 2{Z_L}\)

C \({U_{RC}} \bot {U_{RL}} \to {Z_L}{Z_C} = {R^2}\)

D Khi Z_C=2Z_L thì U_RC max

A \({Z_C} = \frac{{{R^2} + Z_L^2}}{{{Z_L}}}\)

B \({Z_C} = \frac{R}{2}\)

C \({Z_C} = \frac{{{Z_L}}}{2}\)

D \({Z_C} = \frac{{{R^2} + Z_L^2}}{R}\)

A \({Z_{\min }} = R\)

B \({I_{{\rm{max}}}} = \frac{U}{R}\)

C \({P_{{\rm{max}}}} = {I^2}R = \frac{{{U^2}}}{R}\)

D \({\varphi _u} + {\varphi _i} = 0\)

A  \(\frac{{25}}{\pi }\mu F\)

B  \(\frac{{50}}{\pi }\mu F\)

C  \(\frac{{25\sqrt 3 }}{\pi }\mu F\)

D  \(\frac{{100}}{\pi }\mu F\)

A   \(C = \frac{{2,{{5.10}^{ - 4}}}}{\pi }F,{\rm{ }}{U_{Cm{\rm{ax}}}} = 120{\rm{ }}V\)

B  \(C = \frac{{2,{{5.10}^{ - 4}}}}{\pi }F,{\rm{ }}{U_{Cm{\rm{ax}}}} = 240{\rm{ }}V\)

C   \(C = \frac{{5\sqrt 3 {{.10}^{ - 4}}}}{\pi }F,{\rm{ }}{U_{Cm{\rm{ax}}}} = 120{\rm{ }}V\)

D   \(C = \frac{{{{5.10}^{ - 4}}}}{\pi }F,{\rm{ }}{U_{Cm{\rm{ax}}}} = 240{\rm{ }}V\)

A 300 V

B 200 V

C 106 V

D 100 V

A  \(I{\rm{ }} = {\rm{ }}2A\)

B  \(I = \frac{1}{{\sqrt 2 }}A\)

C  \(I = \frac{1}{2}A\)

D  \(I = \sqrt 2 A\)

A  \(u = 60c{\rm{os(100}}\pi {\rm{t - }}\frac{\pi }{2})V\)

B  \(u = 60c{\rm{os(100}}\pi {\rm{t + }}\pi )V\)

C  \(u = 80\sqrt 2 c{\rm{os(100}}\pi {\rm{t + }}\pi )V\)

D  \(u = 80\sqrt 2 c{\rm{os(100}}\pi {\rm{t - }}\frac{\pi }{2})V\)

A  200p rad/s

B  125p rad/s

C  100p rad/s

D  120p rad/s

A \(C = \frac{{50}}{\pi }\mu F,P = 200W\)

B \(C = \frac{{50}}{\pi }\mu F,P = 400W\)

C \(C = \frac{{50}}{\pi }\mu F,P = 500W\)

D \(C = \frac{{50}}{\pi }\mu F,P = 2000W\)

A \(C = \frac{1}{{2500\pi }}F\)

B \(C = \frac{1}{{5000\pi }}F\)

C \(C = \frac{1}{{10000\pi }}F\)

D \(C = \frac{1}{{3000\pi }}F\)

A \({C_0} = \frac{{{C_1} + {C_2}}}{2}\)

B \(\frac{2}{{{C_0}}} = \frac{1}{{{C_1}}} + \frac{1}{{{C_2}}}\)

C \(\frac{1}{{{C_0}}} = \frac{1}{{{C_1}}} + \frac{1}{{{C_2}}}\)

D \({C_0} = {C_1} + {C_2}\)

A Tăng

B Giảm

C Ban đầu tăng, sau giảm

D Ban đầu giảm, sau tăng

A 440 V

B \(220\sqrt 3 V\)

C 220 V

D \(220\sqrt 2 \)

A \(u = 30\sqrt 2 {\rm{cos(100}}\pi {\rm{t + }}\frac{\pi }{6})V\)

B \(u = 40\sqrt 2 {\rm{cos(100}}\pi {\rm{t + }}\frac{\pi }{6})V\)

C \(u = 40\sqrt 2 {\rm{cos(100}}\pi {\rm{t + }}\frac{\pi }{3})V\)

D \(u = 40\sqrt 2 {\rm{cos(100}}\pi {\rm{t + }}\frac{\pi }{2})V\)