EECE 311 Exam, Fall 2000

ELEG 042 Quiz 1 – Fall 2000-2001 – Version A - Page 1 of 4 American University of Beirut Faculty of Engineering and Architecture Department of Electrical and Computer Engineering ELEG 042 - Analog Electronics Instructors: A. Kayssi and Z. Othman Quiz 1 Thursday November 23, 2000 Closed Book Programmable Calculators Are Not Allowed. Time: 1.5 hours VERSION A Name:_______________________________ ID#:__________________________ ► Provide your answer on the computer card only. ► Return the computer card attached to the question sheet. ► Use a pencil for marking your answers and ID number on the computer card. ► When using an eraser, make sure you erased well. ► On this sheet, write with a pen your name followed by your ID number. ► All questions are equally graded. ► Only the computer card will be considered in grading. PENALTY is FOUR to ONE 1. What is the version of your question sheet? (This question is not graded.) a) Version A b) Version B c) Version C d) Version D e) Version E ELEG 042 Quiz 1 – Fall 2000-2001 – Version A - Page 2 of 4 Assume in all problems that: |VBE| = 0.7 V VT = 25 mV β = 100 unless otherwise specified Capacitors are very large Early effect is negligible unless otherwise specified In the circuit of Figure 1, RB = 300K. 2. Find the voltage gain vo/vi. a) –0.81 b) –0.97 c) –1.59 d) –2.34 e) –1.21 3. Find the input resistance Ri in KΩ. a) 380.5 b) 175.8 c) 292.7 d) 339.6 e) 238.7 4. Find the current gain io/ii. a) –41.2 b) –31.0 c) –35.4 d) –38.1 e) –33.0 In the circuit of Figure 2, assume RE = 0.5K. 5. Find the voltage gain vo/vi. a) 0.900 b) 0.928 c) 0.952 d) 0.825 e) 0.943 6. Find Rib2 at the base of Q2 (in KΩ.) a) 203.2 b) 253.9 c) 152.4 d) 101.6 e) 50.8 7. Find Rib1 at the base of Q1 (in MΩ.) a) 16.39 b) 11.36 c) 21.74 d) 27.03 e) 6.17 8. Find the current gain io/ii. a) 396.6 b) 220.1 c) 152.3 d) 94.3 e) 116.5 In the circuit of Figure 3, assume VCC = 12V. 9. Find the voltage gain vo/vi. a) 95.2 b) 75.2 c) 35.3 d) 55.2 e) 115.2 10. Find the input resistance vi/ii in Ohms. a) 8.5 b) 27.3 c) 13.0 d) 17.6 e) 10.3 In the circuit of Figure 4, assume I = 2.5mA. 11. Find the differential voltage gain (vc1 – vc2)/vd, when vB1 = +vd/2 and vB2 = -vd/2. a) –9.9 b) –11.3 c) –12.4 d) –13.2 e) –11.9 ELEG 042 Quiz 1 – Fall 2000-2001 – Version A - Page 3 of 4 12. Find the differential input resistance Rid in KΩ. a) 26.5 b) 30.3 c) 22.7 d) 25.3 e) 24.2 13. Find the input bias current in microAmps when β1=80 and β2=120. a) 12.88 b) 5.15 c) 10.31 d) 20.61 e) 8.24 14. Find the input offset current in microAmps when β1=80 and β2=120. a) 4.08 b) 8.16 c) 5.10 d) 2.04 e) 3.26 15. A differential amplifier has a CMRR of 70 dB. The output voltage is 100 mV when the inputs are v1 = 21.5 mV and v2 = 20 mV. Find the differential gain of this amplifier. a) 66.4 b) 53.5 c) 58.6 d) 46.4 e) 63.9 In the circuit of Figure 5, the MOSFETs have Vt = 2.2V and ½ k’n(W/L) = 1 mA/V2. Neglect body effect and channel length modulation. 16. Find ID in mA. a) 0.090 b) 0.0563 c) 0.116 d) 0.0730 e) 0.160 17. Find gm for the MOSFETs in mA/V. a) 0.600 b) 0.540 c) 0.474 d) 0.800 e) 0.681 18. Find vo1/vs. a) –5.12 b) –5.68 c) –7.58 d) –4.49 e) –6.45 19. Find vo2/vs. a) 18.4 b) 29.3 c) 22.7 d) 40.4 e) 14.2 20. Find ro in KΩ for the MOSFETs given that channel length modulation for AC signals is not negligible and is modeled by λ = 0.1 V-1. a) 62.5 b) 177.7 c) 137.0 d) 111.1 e) 86.2 21. Find Ro in KΩ, given that channel length modulation for AC signals is not negligible and is modeled by λ = 0.1 V-1. a) 16.9 b) 17.5 c) 16.2 d) 15.2 e) 18.0 ELEG 042 Quiz 1 – Fall 2000-2001 – Version A - Page 4 of 4 1000K vi vo 0.1K 10K 10K +10V vi vo 500K 500K 10K RE +12V vi vo Vcc 1K 1K +10V 1K 2K 0.1K 0.1K I Q1 Q2 RB Ri io ii Q2 Q1 Rib2 ii Rib1 io 500K io ii vB1 vB2 vC1 vC2 +12V 300K 300K 100K 20K 20K 10K 10K 50K 10K vo2 vs + 100K vo1 ID Ro Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 ELEG 042 Quiz 1 – Fall 2000-2001 – All Versions - Page 4 of 4