250 bài điện xoay chiều ôn thi đại học

A A B C D cos A B C D l B 0sin(U0 A R, A uR B uR C uL D uC uL, uC L C C so L 0R, 0L U0L, U0C = 2U0R = 2U0C /3 /4 /4 D /4 sai C B TANGIAP.VN A C B sai B A A < > 0 B sai A B C D B A M B TANGIAP.VN > L C D C : B L cos100 t V Khi C = C1 = C2 = F hay C = B L1 C1 L1 A C L1 = L2 L2 1 L2 C2 2 L1 B C1 D 2 1 L2 C2 2 I0cos(100 t + A I0/100 (C) B I0/ 25(C) C I0/50 (C) D 0 A 200W W C W cos100 tV D 300W AB V; 100 o = = 30 , L = R A R = 50 ; PR = 250W C R = 30 ; PR = 250W B.R = 50 ; PR = 62,5W D R = 30 ; PR = 125W A B 300W C W cos100 tV D 200W V A L = B.L = TANGIAP.VN C L = R/ D L 2R/ = t = 45 1, 80 = 1,0 = 0,6 R2 = 0,8 = 0,8 D = 5/3 g A B A 4,5 Wb B Wb C Wb u = U0 u cu n c m thu n l n m ch l d A V D Wb u m t cu n c m thu d n m ch l V t c m A Bi u th c c th D elip uAB uNB A uAN C uAN A t + /3) V t + /3) V 124 C B uAN D uAN 248 D t + /3) V t + /3) V 113 = U0cos( t + /6) V 0cos B tV A 1/300 s B 1/150 s C 1/100 s D 1/50 s A 24V B 100V C 48V D 72V t A 1/400 s B 3/400 s /2 TANGIAP.VN C 1/600 s D 1/150 s /2) V, t u = 200(2 ft) V m D A 60(Hz) B 30(Hz) C 50(Hz) D 480(Hz) u = U0 1 + A L = R1R2 f B L = R1 R2 f D L = AB R1.R2 f C L = 2 = R1 R2 f A R < 20 C R < 16 B R < D R < 25 L A C R D 3R A 10-5 /75 B 10-7s s C 10-6/15 s D 2.10-7s = U0 cos( 100 t + L B C H 2.10 F L H L 0,3 H, x CX CX = 3/ mF CX CX C D R R1 P = 300 W R2 R1 = 0,5625 R2 R1 D TANGIAP.VN = U0cos100 t V Khi u = -50 = A, u = A 50 V B 100 V =C 50 V C< R L< R D V 100 C> R L >R D 2,5.10-8 A 94,4% B 98,2% C 90% D.97,2% Cho R RC C mF mF A.198 B A 20 W mF C.140 cos(100 t) V R = 30V, UC = 80 V, Ud = 10 B 30 W C 40 W D 50 W L(t1) = - 10 V, uC(t1) = 30 V, uR(t1) = L(t2) = 20V, uC(t2)= - 60V, uR(t2) = A 60 V B 50V C 40 V AB = U cos t ( V) AN = 150V; UNB A R0L0 B R0Co C L0C0 B /4 C /4 R = 200V; UC D R0 A /6 D /2 V A 40V B 60V C 100V D 80V C = 0,00005/ A L = 2/5 H u = U0 B L = C L = 3/5 H 5/10 H D L = 1/ H cos10 t V A R= 50 B R=50 TANGIAP.VN 10 F 10 F C R= 10 F 10 F 50 D R=50 C= A B C D nh uAB = UAB cos100 tV, D n1 = 5n2 A 60A B 40A C.50A D 30A AB AM MB A B C D i = I0 t = s, A 2I0 B C 2I0 D I0 cos100 V A D r = 20 1/5 L= u = C 50 , ZL = 50 A 100 V , ZC = 50 3 B 150 V C Khi uAN = 80 MB = 60V uAB V V cos(100 t + ) A A 0,025 s B 0,015 s TANGIAP.VN C 0,035 s D 0,045 s A A rad/s B rad/s C rad/s D rad/s = 1/ (H) A C 3,14.10-5 F C C 1,59.10-5 F B C 6,36.10-5 F D C 9,42.10-5 F - A (1/300) s B (1/150) s C (2/100) s D (1/50) s B C D A B C D A F F F F A 14,628.10-2 H C 3,256.10-2 H B 2,358.10-2 H D 2,544.10-2 H A C B D pha: 90o , UMB AB A R2 = 100 100 50 B R2 F 50 D R2 1, = 100 L2 C2 100 F C R2 tV AB F F V2 AM au MB -4 -5 -4 C TANGIAP.VN L1 C1 F F -3 F L1 A C L1 = 1 2 L2 L2 B L1 D 2 C1 L2 C2 2 -3 C A ud B ud C ud D ud 4) V tA 3A A 24 A B 12 A AB =U C 32A D A cos100 t V B t V Khi C = C1 A Khi C = C2 A 400W B 200 cm C 800 W D 300 W C A ZC = ZL+ 4R2+ZL2 B ZC = ZL+ 4R2+ZL2 C ZC = ZL+ 4R2-ZL2 D ZC = ZL+ 4R2+ZL2 RC 2UR 4R2+ZL2-ZL 2UR RCmax = 4R +ZL2+ZL 2UR RCmax = 4R2+ZL2-ZL 4R2+ZL2 = U.R RCmax +ZL RCmax = U = 3U1 C A 100V TANGIAP.VN B 200V D 200 V 1, L1 2, L2 1, A L1R2 = L2R1 C L1L2 = R2R1 t- )V t + /6 ) A C i = 5cos(100 t - /6 ) A L2 1+U2 10-4 B i = 5cos(100 t + /6 ) A D i = cos(100 t - /6 ) A =5 B 200W C 2000W A D 1500W C A 2, B L1R1 = L2R2 D L1 + L2 = R1 + R2 0cos(100 R1 = 20 A 2500W L1 LC B 2 LC C LC 2 D LC , MB g A 110V B 8V C 10V D 55V u= L C u = U0 1 A 43,3H B 2,86mH 1+ =3 2= D = 27 C 12,7mH AB D 28,6mH u = D 0cos max W B 100W C 200W A R2 = ZL(ZL ZC) C R2 = ZL(ZC ZL) D 300W B R = ZL(ZC ZL) D R = ZL(ZL ZC) Cmax A 50V B 100V C 150V tV A L 10 TANGIAP.VN D 160,5V tV C L C D R L >R 12,5Hz B f 12,5Hz 0cos t (U0 A 0,5 C f < 12,5Hz B 0,85 D f < 25Hz C 22 D 0cos100 B 1/500 D A 1100 B 2200 C 2500 D 2000 AB A t + /6) A t /3) A t + /3) A cos = 0,8 B R C =150V v UMB AB AM B AB = 200 cos100 A UAN = 96V C UAN = 90V B UAN = 72V D UAN = 150V , ZL=60 AB AB = UAN + UNB A R =160 , L = 1/(2 ) H B R =160/3 , L = 1/(3 ) H C R =160 , L = 1/(5 ) H D R =160/3 , L = 1/(5 ) H y , B y c r =20 = 15,9 A 50Hz , L = 1/ C B 100Hz 14 TANGIAP.VN C 61Hz D 41Hz n A 101,2kV; 20,2MW C 101,8kV; 20,8MW B 101,0kV; 20,2MW D 101,0kV; 20,8MW AB t A uNB = 200cos(100 t C uNB = 100cos(100 t A /2 B + /2 =100 , L= 2/ (H) A 10-3/5 (F) C 10-3/25 (F) /2) V /3) V B uNB = 200cos(100 t D uNB = 100cos(100 t C D A v B C B 10-3/ (F) D 1/ 2=1,15s A C 3/(100 ) C = AN =100cos(100 l B 4/(100 ) C D 6/(100 ) C D F A 100 V A 2,5 mWb B 220 V B mWb C 120 V C 0,5 mWb D mWb Khi m A 4,5 A B 1,1 A C 1,8 A D 0,5 A B i = 2.cos C R C B TANGIAP.VN 15 MB= AM A = 44 B 0,1125 A A 0,1 A C 0,05 A D 0,15 A AN MB AN V 1=11 MB AN AN V V D V A i2 = i3 = 6A C i2 = - 3A; i3 = - 3A A 2,4 B i2 = 3A; i3 = - 6A D i2 = 3A; i3 = 3A B C 4,5 D 90 B B xoay d d A B 120 V C 90 V D A 1,8 W B 0,18 W C 1,8m W D 5,5 mW 50 W /3 B 100 A 4P 16 TANGIAP.VN B P C 2P D P/2 A 7,5% B 2,4% C 12% D 4,8% C R f1 = 60 Hz cos = 0,707 A 0,87 cos = f3 B 0,63 f2 = 120 Hz C 0,49 D 0,78 L= m m 1min 10 3 10 C A B V D 10 10 V L A 2A B 0.73A C C A -4 / s A 2.104 1.R2 B 102 C 2.102 D 104 , L=2 = Uocos(2 ft) V A 100Hz B C 40Hz S = 50 cm N B C 11,11V quanh tr A 22.21V uAB = sin100 A uAC C uAC B 0,03V BC = D 15,71 V sin(100 t AC B uAC D uAC - D A /4 B /2 C /12 D /4 0R, 0L U0L, U0C = 2U0R = 2U0C D TANGIAP.VN 17 V B V C 20V D 10V = 2/ A U = 200V B U = 300V D U = 320V = 100 2cos100 = os100 A R = 50 B R = 100 C R = 20 : u = 100sin100 ,t D R = 200 = 100sin(100 t + = 1/ = 16 A R = 200 B R = C R = 100 A 169,7V B 207,85V C 84,85V D 69,28V = 1/ (H) -5 -5 A C 3,14.10 F C C 6,36.10-5 F B C 1,59.10 F D C 9,42.10-5 F f0 LC C A uC C uC B uC D uC h A 50 V C 100 V A 92% B 98% C 94% D 96% A 400 J B 400 J C 1000 J D kJ A 10,98 A B 0,55 A 0cos C 1,10 A D 0,47 A 18 TANGIAP.VN C 4/3 D L A uR = 100cos(100 t + /6) V C uR = 100sin(100 t = = B uR = 100sin(100 t + /3) V D uR = 100sin(100 t /3)V 20 A 0 A P C P/2 D 2P AB MB A 25 V B 50 V C A 10 W A A B 100 W B A C W C A D 0,1 W D 2A D A 23,22 A B 9,67 A C 7,74 A D 29,02 A A TANGIAP.VN 19 A 100 Hz B 200 Hz D 50 Hz = U0 A 1,5 A B 1,2 A C 2,4 A D 0,8 A B 2903 W C 967,7 W D 3267 W A C D A A 322,6 W A B R1 U2 A C = LR1.R2 C L = CR1.R2 B CL = R1.R2 D LR1 = CR2 B 125 rad/s C 128 rad/s D 178 rad/s AN D AB R 20 TANGIAP.VN U1 C AN NB AB U2 B B 240 V C 120 V UC A 1/30 C -4 A 0,9 mW B 0,6 mW C 1,5 mW D 1,8 mW A 12,566 V B 125,6 V C 88,8 V D 88,858 V A 0,5 A B 3,2 A C 5,5 A =6 D 0,8 A d = 90 V d C A D 4,5 A A 347 V B 200 V C 173,5 V D 100 V A 0,5 B 3/4 C 0,86 D 2/3 A f C f2 f12 f22 f12 f22 2 f f 2 1 D 2f f12 f22 B f A TANGIAP.VN 21 B d A 0,095 H B 0,120 H C 0,165 H AM D 0,191 H MB C D ? quay C n stato A 0,96 B 0,87 C 0,50 D 0,707 A B A uR C uR C 2 B uR D uR 3,463) V 1,249) V 1,249) V 0 B R A 22 TANGIAP.VN 1 = 3f1 A cos C cos ;cos ;cos 1 2 B cos 1 D cos ;cos ;cos 2 14 C A = I0 - B I0 C A 200 W B 300 W C 283 W D 400 W L, A U2 U2 L UC U2 R B U2 U2 L UC U2 R C U2 U2 L U2 C U2 R D U2 U2 L U2 C UC, UR U2 R t+ D R1, UC1 R1 = 9UR2 C 0,49 R2, A 0,80 UC2 B 0,75 1 C1 = 16UC2 D 0,25 1? 0t B 200 rad/s A 140 rad/s D 1 A 90 W B 135 W C 125 W D 54 W 0 A L = 1/2 C L = 1/4 TANGIAP.VN = 1/5 mF = 2/5 mF 0 B L = 1/5 D L = 2/5 = 1/2 mF = 1/4 mF 23 ... I0/50 (C) D 0 A 200W W C W cos100 tV D 300W AB V; 100 o = = 30 , L = R A R = 50 ; PR = 250W C R = 30 ; PR = 250W B.R = 50 ; PR = 62,5W D R = 30 ; PR = 125W A B 300W C W cos100 tV D 200W V A L... /6 ) A =5 B 200W C 2000W A D 1500W C A 2, B L1R1 = L2R2 D L1 + L2 = R1 + R2 0cos(100 R1 = 20 A 2500 W L1 LC B 2 LC C LC 2 D LC , MB g A 110V B 8V C 10V D 55V u= L C u = U0 1 A 43,3H B 2,86mH 1+... D - /2 LMax B 100 V C 50 V D 150 V : A 4521W B 1452W : A /6 B /4 A 5000W : u = 100sin100 t V B 2500 W C 4356W D 483,87W C /4 D /12 = 100sin(100 t + C 50W D 2,5W 220 V B C uAB = cos100 t V A uAC