1. Consider the circuit below, representing a common simple two-port system. What name best describes this overall system and its time constant?

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1 Final Exam, Multiple Choice, Scantron 882-E EE 1105 Introduction to EE, Freshman Seminar, Fall 2014 Instructor: Dan Popa, Ph.D. Your Name (Print Clearly) Instructions: Exam time: 2:00 pm 4:30 am (150 mins). You are required to work alone, meaning that no discussion amongst yourselves is allowed. There are fifty questions, each requiring appropriate selection on the Scantron form. In order to receive full credit, you must clearly mark all the correct answers (mark all that apply). Most questions will have only 1 correct answer, but some, require multiple selections. Use of cell phones or scientific calculators during this exam is not allowed. Time management: while it is up to you to manage your time during the exam, you may consider moving on to the next problem after 3 minutes so that you can finish the exam. 1. Consider the circuit below, representing a common simple two-port system. What name best describes this overall system and its time constant? A) A low pass filter with time constant T=R/C B) A high pass filter with time constant T=RC C) A low pass filter with time constant T=RC D) A high pass filter with time constant T=R/C 2. Consider the op-amp circuit below. What name and Gain (G) best describes this circuit? A) A non-inverting amplifier with G=R1/R2 B) An inverting amplifier with G=-R2/R1 C) A non-inverting amplifier with G=(R1+R2)/R2 D) A non-inverting amplifier with G=(R1+R2)/R1

2 3. A voltage divider is designed with two 50 ohm resistors. The input voltage is 10V. When choosing specific parts to construct this, what should the power rating be for each resistor? A) 1 Watt B) 1 Volt-Ampere C) 0.5 Watts D) 0.25 Volt-Amperes 4. You are designing a microcontroller-based system for the measurement of forces 0 to 100N to the nearest 0.1N. It has been determined that the microcontroller will have an ADC converter with a 0-2.5V input range, and that the force sensor has a sensitivity of 0.01V. What should be the best gain of the amplifier placed between the sensor and the ADC, and what is the minimum number of bits that the ADC must have to meet the stated needs? A) A Gain of 1 and 12 bits B) A gain of 1 and 10 bits C) A gain of 0.25 and 10 bits D) A gain of 4 and 10 bits E) A gain of 4 and 12 bits 5. An inductor is (mark all that apply): A) Something that has an inertial effect on current flow B) Something that has an inertial effect on voltage rise/fall C) Something that stores energy in a magnetic field D) Something that stores energy in an electric field 6. A capacitor is (mark all that apply): A) Something that has an inertial effect on current flow B) Something that has an inertial effect on voltage rise/fall C) Something that stores energy in a magnetic field D) Something that stores energy in an electric field 7. A resistor is equivalent to: A) A mass B) A spring C) A damper D) Friction 8. When troubleshooting current, an amp-meter is placed: A) In series with the element under test B) In parallel with the element under test C) In both configurations 9. When troubleshooting voltage, a volt-meter is placed: A) In series with the element under test B) In parallel with the element under test C) In both configurations

3 10. A BJT is: A) A hamburger for electrical engineers B) A current controlled device C) A voltage controlled device D) Requires at least 5V between the base and emitter to turn on 11. The symbol below represents a A) A pnp transistor B) A npn transistor C) A diode D) A FET transistor 12. Assuming that the lossless system below has an initial charge on the capacitor, we wish to draw what the voltage and current response would look like on a XY graph. This graph will look like: A) A circle B) A sine C) A cosine D) An ellipse 13. Let's say you want to use a LED in a 5V circuit in series with a resistor. Assuming the LED drops 0.7V when it is conducting and draws 5 ma. What specifications should you give the person buying the resistor for you? A. Buy any resistor B. Buy a 860 Ohm, 20 W resistor C. Buy a 860 Ohms, 100 mw resistor D. Buy a 1K, 1W resistor E. Buy a 1K, 100 mw resistor 14. A semiconductor is: A. An electronic material that is neither conductive, nor insulating B. An electronic material that is conductive, but has high resistance C. An electronic material that is made of Silicon D. A transistor

4 15. A diode is (mark all that apply) A. A semiconductor device formed by any two p-n junctions B. A nonlinear circuit element C. A current controlled device D. A device that can only works when the voltages applied are less than 0.7 V E. Something that only allows current to flow one way 16. Consider a flashlight that has two AA batteries. What parameters need to be known in order to estimate how long the flashlight can produce light continuously? A. The resistance of the bulb and the electrical energy stored in the batteries B. The power rating of the bulb and the battery C. The current rating of the bulb and the electrical energy stored in the batteries D. The voltage rating of the bulb and the power of the battery E. The time the ON switch of the flashlight is pressed 17. The 3 intellectual themes of Electrical Engineering are: A. Hardware, Software, Experimentation B. Modularity, Abstraction, Modeling C. Sensing, Processing, Actuation D. Analysis, Experimentation, Synthesis E. Math, Physics, and Electricity 18. Which EE system could best be described as linear? A. A resistive circuit B. A transistor circuit C. A digital circuit D. A mechatronic system 19. Pick the best example of system that employs black box models for its operation: A. Lawn Mower driven by a human operator B. Pressure sensor with bridge circuit and microcontroller C. Armature controlled DC motor D. Circuit with resistor series connection 20. The role of feedback control is to: A. Provide a systematic way to predict the system response, and offer analysis and design based on desired characteristics. B. Reduce sensitivity to system parameters, reject disturbances, track desired inputs with reduced steadystare errors, overshoot, rise time, settling time. C. Reduce the estimation errors from sensors, and minimize the energy consumed by the actuators of a robot.

5 21. A current divider consists of two resistors with values of R1=1KΩ and R2=2KΩ, respectively. If the current flowing through R1 is I1=1A, then the current flowing through R2 will be: A. 2A B. 2V C. 0.5 A D. 1A E. 1V 22. A voltage divider consists of two resistors with values of R1=1KΩ and R2=2KΩ, respectively. If the current flowing through R1 is I1=1mA, then the voltage across R2 will be: A. 2A B. 2V C. 0.5 A D. 0.5 V E. 1V 23. A mesh in a circuit is defined as: A. A closed path with the same start and end node B. A loop containing one or more branches not contained in any other loop C. A loop that encloses no other loop D. A continuous set of branches with no node encountered more than once 24. The direction of electric current in a wire is: A. In the same direction of electron flow B. In the opposite direction of electron flow C. Dependent on the movement of both electrons and protons D. From positive voltage to negative voltage across the wire 25. A circuit open is defined as: A. A switch in the OFF position B. Zero resistance between two nodes C. Infinite resistance between two nodes D. None of the above 26. Silver has a conductivity σ=61.7 MS/m. The resistance of a conductor made of silver with a cross sectional area A=1 mm 2 and a length of 100m is: A Ohm B K C Ohm D K E. I don t remember the formula for this 27. Kirchoff s Voltage Law KVL is a statement of conservation of A. Charge B. Energy C. Voltage

6 28. What conditions must be satisfied for two circuits to be equivalent between nodes 1 and 2 A. They must have the same topology between the nodes B. They must have the same power between the nodes C. They must have the same voltage and current across the nodes D. All of the above 29. Two circuits with identical Thevenin equivalents (Vth, Rth) are connected to each other. The resulting circuit has the following equivalent: A. Vth, Rth B. Vth, 2Rth C. Vth, Rth/2 D. 2Vth, 2Rth E. 2Vth, Rth 30. The circuit diagram in the figure below (Exercise 2-9) has an equivalent resistance equal to: A. 15 Ohms B. 0 Ohms C. 30 Ohms D Ohms 31. Determine the current I flowing through the circuit below (Exercise 3-1) A. 0.2 A B. 5 A C. 0.5 A D. None of the above E. I don t understand how to do this

7 32. Explain why the linearity property of electric circuits is an underlying requirement for the application of source superposition method. A. The two are the same concept B. It can be shown that a nonlinear circuit with source superposition property leads to a contradiction C. There must be another explanation 33. Pick one of the statements that best describes semiconductor fabrication processes: A. Repeated Implantation, Deposition and Etching B. Lithography, Irradiation, Bonding, Dicing C. Dispensing, Spinning, Baking, Developing 34. A circuit will transfer maximum power to a resistive circuit when: A. The load will consume a fourth of generated power. B. The Thevenin equivalent resistances of the two circuits are equal. C. The Norton equivalent resistances of the two circuits are zero. D. One of the circuit ports is connected to ground. 35. After converting the decimal number 12 to base 2, the result is: A B C D E If the current through a resistor decays exponentially with a time constant τ, what is the value of the power dissipated by the resistor at time t=τ? A. 50% B. 100% C. 63% D. 10% 37. If two identical capacitors are connected in series, the equivalent capacitance: A. Stays the same B. Doubles C. Halves D. It depends on the capacitor type 38. A band pass filter is a circuit that: A. Attenuates high frequency inputs and amplifies low frequency inputs B. Attenuates both low and high frequency inputs C. Does not attenuate low and high frequency inputs D. Amplifies input signals in a narrow band

8 39. Two identical inductors are connected in series. What do you expect of the power dissipated by the overall circuit when compares to individual inductors: A. It halves B. It stays the same C. It doubles D. It changes, but in a different way 40. An operational amplifier is used in negative feedback mode, by connecting the output to its non-inverting input with a piece of wire. The function of this circuit can be described as: A. A comparator B. A voltage follower C. An amplifier D. An attenuator 41. In course number EE 3417 of the EE curriculum at UT Arlington you will study: A. Continuous Signals and Systems B. Electromagnetics C. Discrete Signals and Systems D. Control Systems E. Do I have to remember this?? 42. Optics and Photonics is a field of EE that is based on electromagnetic theory as derived from Maxwell s equations. The most important applications of this field, in terms of impact to our economy and society are: A. Fiber optics, Telecommunications, Light Sources B. RFID, Sensors, Solar Cells C. Fiber optics, Radio and TV, Biosensors D. Holography, Lasers, Microscopy E. Astronomy, Space technology, Solar Cells 43. How does the value of wavelength of an optical signal in the visible spectrum compare to the wavelengths the UV part of the spectrum: A. It is slightly higher B. It is slightly smaller C. It is considerably smaller D. It is considerably higher E. It is the same 44. Radar is used to detect the distance between an EM source and an incoming object via time-of-flight of the waves, which is approximately 3x10 8 m/s. If the time delay registered between an emitted pulse and received pulse is t=1µs, what is the expected distance to the target? A. 1 km B. 1 m C. 150 m D. 750 m

9 45. When writing the equations of motion of an armature controlled DC motor, one must consider the following effects (select the most appropriate): A. Lorentz forces B. Maxwell s equations C. Newton- Euler s law. D. All of the above E. The above and other equations 46. Civilian Applications of Pulsed Power include (select all that apply): A. Magnetic Forming of Metals B. Civilian Radar C. Rail Guns D. Stun Guns 47. The wavelength range of commercial lasers used in LIDAR applications include: A. Xray, UV, Visible bands B. UV, Visible, IR band C. Gamma, Xray, UV band D. Visible and IR band 48. PID control stands for: A. Predictive, Integrated, and Dynamic Control B. Proportional, Integral, Derivative Control C. Processing, Integration, and Deployment Controller D. None of the above 49. A robot is defined as a: A. An entity that can sense, think and act. B. An entity that can navigate and explore unknown environments C. A mechanical structure controlled by feedback control D. A machine that can imitate humans 50. As I have taken and survived EE 1105, Freshman Seminar, and I now realize that I will need to pay a lot of attention to: A. Linear Algebra, Differential Equations, Calculus, Physics B. Discrete mathematics and Computer Programming C. Abstract and algorithmic thinking D. Hands on skills for testing and debugging of circuits