* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download EE2010 - Final Term Exam
Standing wave ratio wikipedia , lookup
Regenerative circuit wikipedia , lookup
Immunity-aware programming wikipedia , lookup
Audio power wikipedia , lookup
Josephson voltage standard wikipedia , lookup
Index of electronics articles wikipedia , lookup
Operational amplifier wikipedia , lookup
Schmitt trigger wikipedia , lookup
Valve audio amplifier technical specification wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Opto-isolator wikipedia , lookup
Electrical ballast wikipedia , lookup
Power electronics wikipedia , lookup
Two-port network wikipedia , lookup
Surge protector wikipedia , lookup
RLC circuit wikipedia , lookup
Valve RF amplifier wikipedia , lookup
Current mirror wikipedia , lookup
Current source wikipedia , lookup
Power MOSFET wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Answer the Following Questions: Question No. (1) 4 marks(16x0.25) Calculate the Requirements and Choose the Correct Answer: 1- An electric circuit consists of a voltage source V=100 V in series with a resistor R. If the current flows in the circuit is 10 A, the value of R equals to: (a) 0.01K (b) 0.1 (c) 100 (d) 1 2- An electric circuit with resistors 2 , 4 , 6 , and 8 are connected in parallel. The equivalent resistor equals to: (a) 0.96 (b) 0.93 (c) 0.9 (d) 0.98 3- An electric circuit consists of a voltage source V=200 V in series with two resistors of 25 Kand 100 K. The out put voltage across the 100 K resistor equals to: (a) 120 V (b) 132 V (c) 140 V (d) 160 V 4- An electric circuit consists of a current source with I=20 A and two resistors 16 and 4 . All elements are connected in parallel. The current flows in the 4 resistor equals to: (a) 16 A (b) 0.16 A (c) 8 A (d) 0.8 A 5- An electric circuit consists of a current source with I=8 A and four resistors 80 , 10 , 80 and 24 . All elements are connected in parallel. Using the current division method, the current flows in the 24 resistor equals to: (a) 20 A (b) 2 A (c) 0.2 A (d) 0.02 A 6- A delta connection with resistors (100 , 125 , 25 ), the corresponding wye connection resistors equal to: (a) (50 , 12.5 , 10 ) (b) (25 , 25 , 20 ) (c) (100 , 25 , 20 ) (d) (150 , 50 , 10 ) 1-15 7- For the circuit shown in the Fig. B-1, the Thevenin impedance at terminals a-b is: (a) 1 Ω (b) 0.5 − j0.5 Ω (c) 0.5 + j0.5 Ω (d) 1 + j2 Ω (e) 1 − j2 Ω Fig. 1-7 8- In the circuit of Fig. B-1, the Thevenin voltage at terminals a-b is: (a) 3.535 − 45◦ V (b) 3.535 45◦ V (c) 7.071 − 45◦ V (d) 7.071 45◦ V 9- The value of the current Io in the circuit in Fig. B-2 is: (a) 4 0◦ A (b) 2.4 − 90◦ A (c) 0.6 0◦ A (d) −1 A Fig. 1-9 10- The Thevenin impedance of a network seen from the load terminals is (80 + j55) Ω. For maximum power transfer, the load impedance must be: (a) (−80+j55) Ω (b) (−80−j55) Ω (c) (80−j55) Ω (d) (80+j55) Ω 11- A certain passive network has equivalent impedance Z=(3+j4) and an applied voltage v 42.5 cos(100 t 30) V 11-1 The effective voltage equals to: (a) Veff 42.5l 230 V (b) Veff 42.530 V (c) Veff 42.5l 2 30 V (d) Veff 42.5l 2100 V 2-15 11-2 The effective current equals to: (a) I eff 8.5 23.13 A (b) I eff 8.523.13 A (c) I eff 8.5l 2 23.13 A (d) I eff 8.5l 230 A 11-3 The complex power equals to: (a) S 18.0653.13 VA (c) S 180.653.13 VA (b) S 361.253.13 VA (d) S 180.6 53.13 VA 11-4 The average power equals to: (a) P = 108.4 W (b) P = 1084 W (c) P = 144.5 W (d) P = −108.4 W 11-5 The reactive power equals to: (a) Q = 1445 VAR (c) Q = −144.5 VAR (b) Q = 144.5 VAR (d) Q = 108.4 VAR 11-6 The power factor equals to: (a) P.F = 0.6 leading (c) P.F = 0.8 lagging (b) P.F = 0.6 lagging (d) P.F = 0 3-15 Question No. (2) For the circuit shown in Figure (2), find the following: 2(0.5+0.5+0.5+0.5) marks (a) The current in the 30 resistor using current divider, (b) The current in the 25 resistor using current division, (c) The voltage v2 using the voltage divider, (d) The power associated with the independent source. 12 50 30 + 25 A v1 + - v2 25 60 30 - Figure (2) Question No. (2) 4-15 Question No. (3) 14 marks (3-A) 3.5 (1.5+1+1) marks Use the node-voltage method in the circuit shown in Figure (3-A) to determine the following: (a) The power associated with all sources, (b) The power dissipated in all resistor, (c) Verify that the power dissipated or absorbed equals to the power delivered in the circuit shown in Figure (3-A). 4 2 5V 20V 4A 3 5 Figure (3-A) Question No. (3-A) 5-15 (3-B) 3.5 (1.5+0.5+1+0.5) marks Use the mesh-current method for the circuit shown in Figure (3-B) to find the following: (a) The power dissipated in the 2 resistor, (b) The power associated with the all sources, (c) The voltage V. 10 A 2 1 + 75 V ia V 5 - Figure (3-B) Question No. (3-B) 6-15 2V 5 (3-C) 4 (2.5+0.5+0.5+0.5) marks For the circuit shown in Figure (3-C), find the following: (a) The Thevenin equivalent circuit with respect to terminals (a, b), (b) The value of the resistor R that enables the circuit shown to deliver the maximum power to the terminals (a, b), (c) The maximum power delivered to the resistor R, (d) If a resistor 150 is connected across the terminals (a, b), find the power dissipated in this resistor using Thevenin theorem. 20 160i a i 60 4A 80 + 40 b Figure (3-C) Question No. (3-C) 7-15 (3-D) 3 (1+1+1) marks For the circuit shown in Figure (3-D), find the following: (a) The voltage V using source transformation, (b) The delivered power by the 72 V source, 48 source, and 30 A source, (c) The power dissipated in the 6 resistor. 12 4 + 30 A 6A 6 V - 72 V 48 V Figure (3-D) Question No. (3-D) 8-15 10 Question No. (4) 10 marks (4-A) 3 (1.5+0.5+0.5+0.5) marks Use the node-voltage method for the circuit shown in Figure (4-A) to find the following: (a) The current in each branch, (b) The voltage across the 20 resistor, (c) The steady-state expression for the voltage and current across the capacitor, is=15 cos (t), Vs=200 sin (t), = 4000 rad/sec. 20 + is 5 V 9 mF 100 mH - Figure (4-A) Question No. (4-A) 9-15 Vs (4-B) 3 (1.5+0.5+0.5+0.5) marks Use the mesh-current method for the circuit shown in Figure (4-B) to find the following: (a) The steady state expression for current I, (b) The voltage across the 2 resistor, (c) The steady-state expression for Vx(t). 1 j2 I Vs 33.80 V 3 + Vx -j5 - Figure (4-B) Question No. (4-B) 10-15 0 . 75 V x 2 (4-C) 4 (2.5+0.5+0.5+0.5) marks For the circuit shown in Figure (4-C), use the Thevenin theorem to find the following: (a) The Thevenin equivalent circuit with respect to the terminals (a, b), (b) The current Ix., (c) The power dissipated in the 12 resistor, (d) The steady state expression for voltage V2. j2 j3 1 1 a + 1500 V V1 - + + 12 V2 Ix -j16 - b Figure (4-C) Question No. (4-C) 11-15 V3 39I x Question No. (5) (5-A) For the circuit shown in Figure (5-A) find the following: (a) The value of the voltage between the terminals (a, b), (b) The power dissipated in the 120 resistor, (c) The voltage across the capacitor. -j40 12 6 marks 3 (2+1+1) marks 120 a + 120Ð 0 V Vx 60 10 Vx - b Figure (5-A) Question No. (5-A) 12-15 (5-B) For the circuit shown in Figure (5-B) determine the following: (a) The voltage across the 2 resistor, (b) The power dissipated in the 7.5 resistor, (c) The power associated with all sources. 4 2.5 2 + 193 V V + 0.4V V 0.5 A 3 (1+1+1) marks 6 - + V 7.5 - 8 Figure (5-B) Question No. (5-B) 13-15 0.8V Question No. (6) 4 marks (1+1+1+1) For the circuit shown in Figure (6), a practical voltage source formed by an ideal voltage source Vg 320 20 in series with an impedance Zg feeds a load ZL. (a) Find the average power Pg and the reactive power Qg and the apparent power S delivered by the voltage source, (b) Find the average power PL and the reactive power QL absorbed by the load. (c) Find the power factor of the load, (d) Determine the value of the capacitor that would correct the power factor to unity if it is placed in parallel with the load. Note (the source frequency is 60 Hz) Zg j100 50 I j100 Vg=320√2 0° Load : ZL 200 Figure (6) Question No. (6) 14-15 15-15