Final Exam Guide for ECE 2070: Key Concepts & Practice Questions

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Clemson University**We aren't endorsed by this school

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ECE 2070

Subject

Electrical Engineering

Date

Dec 12, 2024

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Uploaded by BailiffRoseOpossum17

ECE 2070 Section 002 Final ExamFriday May 6, 202235 questions with equal weight, Q36 is BONUS Question, 150 minutesFill in your last name, first name, and middle initial on the Scantron sheet.Fill in the proper circle on the Scantron sheet as you solve problems. Please usepencilto mark correctanswer on the scantron sheet. Exams will be collected promptly at the end of the period. You will notbe given extra time to fill in your answers.Note: Answers have been rounded after solving. Please choose answers that aregenerally close(byyour estimation and within reason). Be very careful when choosing the “None of the above” option.Begin QuizVersion A1.The version of my exam (printed directly above) is(a)•A(b) B(c) CFigure 1: For Questions 2 and 3.2.For the circuit shown in Figure 1, which of the following is true?(a)•4 Ω resistance is in series with the 5 Ω resistance.(b) 2 Ω resistance is in series with the 6 Ω resistance.(c) 7 Ω resistance is in series with the 3 Ω resistance.(d) 4 Ω resistance is in series with the 7 Ω resistance.(e) None of the above3.For the circuit shown in Figure 1, what is the value ofReq?(a)Req= 3.4 Ω(b)Req= 20 Ω(c)Req= 13 Ω(d)•Req= 9.8 Ω(e) None of the above1

Figure 2: For Questions 4, 5, 6 and 7.For Questions 4, 5, 6 and 7,V1= 4V,V2= 1V,R1= 12 Ω,R2= 6 Ω andR3= 10 Ω.4.For the circuit shown in the Figure 2, what is the Node Voltage equation for the node specified withvoltageVa?(a)•Va−412+Va6+Va−110= 0(b)Va−412+Va−110= 0(c)Va−412+Va6= 0(d)Va+412+Va6+Va−110= 0(e) None of the above5.For the circuit shown in the Figure 2, what is the value ofVa?(a)•Va= 1.24V(b)Va= 7.23V(c)Va= 3.45V(d)Va= 5.21V(e) None of the above6.For the circuit shown in the Figure 2, what is the value of magnitude of current throughR1?(a) 47mA(b) 410mA(c) 22mA(d)•230mA(e) None of the above7.For the circuit shown in the Figure 2, what is the value power absorbed inR2?(a) 2.44W(b) 1.98W(c) 4.32W(d)•0.26W(e) None of the above2

Figure 3: For Questions 8 and 9.8.For the circuit shown in the Figure 3, what is the value of open circuit Thevenin equivalent voltageVthat nodesa−b? (Please note that the load resistance is removed from the nodesaandb).(a)Vth= 7V(b)Vth=−10V(c)•Vth=−3V(d)Vth= 0V(e) None of the above9.For the circuit shown in the Figure 3, what is the value of Thevenin equivalent resistanceRthat nodesa−b? (Please note that the load resistance is removed from the nodesaandb).(a)Rth= 2 Ω(b)Rth= 4 Ω(c)Rth= 3 Ω(d)•Rth= 1 Ω(e) None of the above10.Given the phasor form currentI(jω) = 33∠−60◦mAin frequency domain, what is the currenti(t) inthe time-domain if frequencyf= 3.18Hz?(a)•i(t) = 33 cos(20t−60◦)mA(b)i(t) = 0.033 cos(20t+ 60◦)mA(c)i(t) = 33 cos(0.5t−60◦)mA(d)i(t) = 0.033 cos(0.5t+60◦)mA(e) None of the above11.Given the voltage in time-domain asv(t) = 240 cos(377t+π6)V, what is the phasor voltageV(jω) inthe frequency domain?(a)V(jω) = 240∠180◦V(b)•V(jω) = 240∠30◦V(c)V(jω) = 377∠38◦V(d)V(jω) = 377∠180◦V(e) None of the above3

For Questions 12 and 13, the time-dependent voltage isv(t) = 10 cos(3πt+3π2)V.12.What is the frequency ofv(t) in Hertz?(a)f= 9.2Hz(b)f= 3.0Hz(c)f= 4.6Hz(d)•f= 1.5Hz(e) None of the above13.What is the phase angle of the voltagev(t) in degrees?(a) 90◦(b) 45◦(c)•270◦(d)−45◦(e) None of the aboveFigure 4: For Questions 14 and 15.14.For circuit shown in Figure 4, what is the value of impedance for 150mHinductor ?(a)j26 Ω(b)j16 Ω(c)•j45 Ω(d)j34 Ω(e) None of the above15.For circuit shown in Figure 4, the load consists of everything to the right of nodesaandb. What is thepower factor of the load?(a) 0.189leading(b) 0.987lagging(c) 0.432leading(d)•0.316lagging(e) None of the above4

Figure 5: For Questions 16, 17 and 18.16.For the circuit shown in the Figure 5 which of the following is the correct dependent source present inthe circuit ?(a) Current controlled current source(b) Current controlled voltage source(c) Voltage controlled current source(d)•Voltage controlled voltage source(e) None of the above17.For the circuit shown in the Figure 5,i1andi2are Mesh currents forMesh1 andMesh2 respectively.What is KVL equation forMesh1 ?(a)•11(i1−i2) +vx+15vx= 0(b) 11i2+vx+15vx= 0(c) 11(i1+i2) +15vx= 0(d) 11i1+vx+15vx= 0(e) None of the above18.For the circuit shown in the Figure 5, what is the value of currenti1?(a)i1= 2.75A(b)i1= 0.52A(c)•i1= 1.04A(d)i1= 3.38A(e) None of the aboveFigure 6: For Question 19.19.For the circuit of ideal transformer shown in Figure 6, what isn2ifn1= 510 ?5

(a)n2= 298(b)n2= 85(c)n2= 42(d)•n2= 3060(e) None of the aboveFigure 7: For Question 20.20.For the circuit shown in Figure 7, What is the equivalent capacitance between nodesaandbforC1=9mF,C2= 9mFandC3= 9mF?(a)Ceq= 9mF(b)Ceq= 3mF(c)•Ceq= 27mF(d)Ceq= 0.33mF(e) None of the above6

Figure 8: For Questions 21 and 22.21.For the circuit shown in Figure 8, which of the following is true?(a) For the 4 Ω resistor current leads voltage with 120◦.(b) For the 4 Ω resistor current lags voltage with 90◦.(c)•For the 4 Ω resistor current is in phase with the voltage.(d) For the 4 Ω resistor current leads voltage with 90◦.(e) None of the above22.For the circuit shown in Figure 8, what is the value ofZT?(a)ZT=j4 Ω(b)•ZT= 4 Ω(c)ZT= 20 Ω(d)ZT=j8 Ω(e) None of the above7

Figure 9: For Questions 23 and 24.For Questions 23 and 24.For the circuit shown in Figure 9, the following mesh currents are given:ia= 1A,ib=−231mA,ic= 334mAandid= 806mA.23.What is the value of the voltageva?(a)−2.84V(b) 3.91V(c)−1.69V(d)•5.64V(e) None of the above24.What is the value of the voltagevd?(a) 1.72V(b)−2.84V(c)•−1.69V(d) 3.91V(e) None of the above25.What is the rectangular form of (4∠18◦+ 5∠12◦)?(a)•8.69 +j2.28(b) 17.32 +j10(c) 10.32 +j3.4(d) 3.97 +j2.9(e) None of the above8

Figure 10: For Questions 26, 27, 28, 29 and 3026.For the circuit shown in Figure 10, what is the impedance of the capacitor in the frequency domain ?(a)•−j1.5 Ω(b)−j2 Ω(c) 3 Ω(d)j6 Ω(e) None of the above27.For the circuit shown in Figure 10, what is the impedance of the inductor in the frequency domain ?(a) 3 Ω(b)−j2 Ω(c)•j6 Ω(d)−j1.5 Ω(e) None of the above28.For the circuit shown in Figure 10, what is the impedance of the resistor in the frequency domain ?(a)−j2 Ω(b)j6 Ω(c)•3 Ω(d)−j1.5 Ω(e) None of the above29.For the circuit shown in Figure 10, what is the time dependent voltage across the capacitorv(t)?(a)v(t) = 8.2 cos(2t−99◦)(b)•v(t) = 16.7 cos(2t−56◦)(c)v(t) = 16.7 cos(2t−99◦)(d)v(t) = 8.2 cos(2t−56◦)(e) None of the above30.For the circuit shown in Figure 10, what is the time dependent current through 3 Ω resistor?(a)•i(t) = 5.57 cos(2t−56◦)(b)i(t) = 24.6 cos(2t−56◦)(c)i(t) = 5.57 cos(2t−34◦)(d)i(t) = 24.6 cos(2t−34◦)(e) None of the above9

Figure 11: For Questions 31, 32, 33 and 34.31.For circuit shown in Figure 11, considering ideal diode, what is the value of current through diodeiD?(a)•iD= 2A(b)iD= 0.5A(c)iD= 0.62A(d)iD= 0A(e) None of the above32.For circuit shown in Figure 11, considering ideal diode, what is the value of voltage across the diodevD?(a)vD=−14V(b)•vD= 0V(c)vD= 3.5V(d)vD= 10.5V(e) None of the above33.For circuit shown in Figure 11, considering ideal diode, what is the value of voltage across the 3 Ωresistor?(a)v3Ω=−14V(b)•v3Ω= 0V(c)v3Ω= 3.5V(d)v3Ω= 10.5V(e) None of the above34.For circuit shown in Figure 11, considering ideal diode, what is the value ofix?(a)ix= 0A(b)ix= 0.62A(c)ix= 0.5A(d)•ix= 2A(e) None of the above10

Figure 12: For Question 35.35.For the ideal op-amp based inverting amplifier circuit shown in Figure 12,R1= 500 Ω andR2= 2kΩ.What is the gainAv=voutvin, of the given circuit?(a)•Av=−4(b)Av= 5(c)Av= 1(d)Av=−10(e) None of the aboveQ36 is BONUS Question:Q36 (if correct) will replace one incorrect answer from Q1-Q35.Q36 (ifincorrect) will not change your score for Q1-Q35.Q36 (if correct) and if you have all correct fromQ1-Q35, this will not change your score for Q1-Q35.36.If two complex numbersAandBare given as,A= 20∠90◦andB= 10∠−90◦, what isC=A+B?(a)C= 10∠0◦(b)C= 15∠0◦(c)C= 5∠90◦(d)•C= 10∠90◦(e) None of the aboveEnd Quiz11