An Electronics Test

IN ANSWERING QUESTIONS 1 AND 2, REFER TO FIGURE 3H. 1. What is the value of total resistance? 1. 5Ω 2. 8Ω 3. 13Ω 4. 15Ω 2. If an equivalent resistor is used to represent the network of R1, R2, R3, R4, R5, and R6, what is the total voltage drop across this resistor? 1. 8V 2. 26V 3. 52V 4. 60V

IN ANSWERING QUESTIONS 3 THROUGH 8, REFER TO FIGURE 3I. 3. Why must the value of R1 be calculated first? 1. For convenience 2. The current through R2 depends on the value of R1 3. The voltage drop across R1depends on the value of load 1 4. In any circuit, values for resistors labeled R1 are calculated first

4. How is the current through R2 calculated? 1. By adding IR1 and the current requirement of load 1 2. By adding the current requirements of load 1 and load 2 3. By subtracting the current requirement of load 1 from the current requirement of load 2 4. By subtracting the current requirement of load 2 from the current requirement of load 1 5. How is the voltage drop across R2 calculated? 1. By adding the voltage requirements of load 1 and load 2 2. By subtracting the voltage drops across R5 and R 3 from the source voltage 3. By subtracting the voltage requirement of load 1 from the voltage requirement of load 2 4. By subtracting the voltage requirements of load 1 and load 2 from the source voltage 6. What is the total power supplied by the source? 1. 3.765 W 2. 7.965 W 3. 8.209 W 4. 8.965 W

IN ANSWERING QUESTIONS 7 THROUGH 9, REFER TO FIGURE 2A. 7. What waveform is an illustration of the voltage (ES) present across the voltage divider when switch S1 is closed? 1. B 2. C 3. E 4. G 8. The voltage dropped across R when switch S1 is closed is depicted in which of the following waveforms? 1. G

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2. H 3. F 4. C 9. The voltage developed across L when switch S1 is closed is depicted in what waveform? 1. A 2. B 3. E 4. H

IN ANSWERING QUESTIONS 10 THROUGH 14, REFER TO FIGURE 4A 10. What is the value of X? 1. 19.7 2. 27.8 3. 31.6 4. 42.3 11. What is the value of Z? 1. 23 2. 28 3. 33 4. 38 12. What is the value of IT otal for the circuit? 1. 1.8 A 2. 2.8 A 3. 3.4 A 4. 4.4 A 13. What is the value of true power? 1. 67 W 2. 83 W 3. 94 W 4. 125 W

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14. What is the power factor? 1. .46 2. .52 3. .73 4. .88 15. A transformer secondary has 20 amperes of current flowing at 60 volts potential. The applied voltage is 10 volts. What are (a) the turn’s ratio of the transformer and (b) what total current is flowing in the primary? 1. (a) 6:1, (b) 3.3 amperes 2. (a) 1:6, (b) 120 amperes 3. (a) 1:2, (b) 10 amperes 4. (a) 2:1, (b) 120 amperes 16. The class of operation of an amplifier is determined by which of the following factors? 1. The gain of the stage 2. The efficiency of the amplifier 3. The amount of time (in relation to the input signal) that current flows in the output circuit 4. The amount of current (in relation to the input-signal current) that flows in the output circuit 17. Which of the following is NOT a class of operation for an amplifier? 1. A 2. C 3. AB 4. AC

IN ANSWERING QUESTIONS 18 AND 19 REFER TO FIGURE 1A. 18. What are the (a) upper and (b) lower frequency limits shown? 1. (a) 8 kHz (b) 0 Hz 2. (a) 7.5 kHz (b) 0 Hz

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3. (a) 6.0 kHz 4. (a) 5.5 kHz

(b) 2 kHz (b) 2.5 kHz

19. What is the bandwidth shown? 1. 1 inch 2. 8 kHz 3. 3 kHz 4. 2 kHz to 8 kHz 20. A diode is an ideal rectifier for which, if any, of the following reasons? 1. Current flows through the diode in one direction only 2. Current flows through the diode in both directions 3. Current will not flow through a diode 4. None of the above 21. When the anode of a diode is negative with respect to the cathode, the diode is said to be in what state? 1. Conduction 2. Saturation 3. Remission 4. Cutoff

IN ANSWERING QUESTIONS 22 AND 23, REFER TO FIGURE 4-B. 22. When the voltage across the secondary of the transformer has the polarity shown, which of the diodes will conduct? 1. D1 and D3 2. D2 and D4 3. D1 and D2

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4. D3 and D4 23. When the polarity reverses, which of the diodes will conduct? 1. D3 and D1 2. D4 and D2 3. D2 and D1 4. D4 and D3

IN ANSWERING QUESTIONS 24 THROUGH 26, REFER TO FIGURE 4-E. 24. The base-emitter bias across Q1 is determined by which of the components? 1. R1 and CR1 2. R1 and RS 3. RS and CR1 4. RS and RL 25. What, if anything, happens to the forward bias of Q1 when the input voltage increases? 1. It increases 2. It decreases 3. Nothing, it remains the same 26. When the load current increases and the output voltage momentarily drops, what, if anything, happens to the resistance of Q1? 1. It increases to compensate for the drop 2. It decreases to compensate for the change 3. Nothing, it remains the same

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WHEN ANSWERING QUESTIONS 27 AND 28, REFER TO FIGURE 4K. 27. Assume only FF 1 and FF 3 are set. Which, if any, of the flip-flops will be set after the next clock pulse? 1. FF 2 only 2. FF 3 only 3. FF 2 and FF 3 4. None 28. Assume that all FFs are set, which of the following actions will take place at clock pulse 4? 1. FF 1, FF 2 and FF 3 will set 2. FF 1 will set, FF 2 and FF 3 will reset 3. FF 1, FF 2, and FF 3 will reset 4. FF 1 and FF 2 will set, FF 3 will reset

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WHEN ANSWERING QUESTIONS 29 AND 30, REFER TO FIGURE 4L. 29. Which of the following methods will clear the register of old information no longer needed? 1. A HIGH applied to the READ IN line 2. A HIGH applied to the RESET line 3. A LOW applied on the RESET and a HIGH on the READ OUT lines 4. HIGHs are applied on the A, B, C, D, and READ IN lines 30. Under which of the following conditions will the output of gate 7 be HIGH? 1. When FF 3 and RESET are HIGH 2. When gate 3 and FF 3 are HIGH 3. When FF 3 and READ OUT are HIGH 4. When the output of gate 3 is HIGH 31. What is the hex equivalent of 4510? 1. 1F16 2. 2416 3. 2A16 4. 2D16 32. What is the hex equivalent of 25510? 1. AE16 2. BC16 3. CG16 4. FF16

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33. Which, if any, of the following types of variable resistors is used to control a large amount of current? 1.Rheostat 2.Potentiometer 3.Wirewound potentiometer 4.None of the above 34. A carbon resistor is color-coded orange, orange, orange. What is the resistance value of this resistor? 1.2.2 kΩ 2.3.3 kΩ 3.33.0 kΩ 4.440.0 kΩ 35. What is the approximate frequency of an ac voltage that has a period of .0006 second? 1.6 Hz 2.16.67 Hz 3.600 Hz 4.1667 Hz

IN ANSWERING QUESTION 36, REFER TO FIGURE 2C. 36. The symbol shown in the figure is found on a component package. What does it indicate about the component? 1. It is a high cost item 2. It is a bipolar device 3. It is an integrated circuit 4. It is electrostatic discharge sensitive IN ANSWERING THE FOLLOWING QUESTIONS SELECT FROM THE FOLLOWING LIST THE LOGIC OPERATION DESCRIBED IN THE QUESTION. A. AND B. OR C. NOT D. NOR E. NAND F. INHIBIT G. EXCLUSIVE OR 37. A combination of an OR operation and a NOT operation.

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1. A 2. C 3. D 4. E 38. An input signal produces no output, while a no-signal input state produces an output signal. 1. B 2. C 3. F 4. G 39. When a signal is present at every input terminal, no output is every produced. 1. D 2. E 3. F 4. G 40. Which of the following is a typical use for a megger? 1. Testing MOSFETs 2. Testing filter capacitors 3. Testing thermistor mounts 4. Testing an ac power cord for insulation breakdown 41. Which of the following pieces of test equipment should you use to determine what signals make up a complex signal? 1. Oscilloscope 2. Sweep oscillator 3. Spectrum analyzer 4. Time-domain reflectometer 42. Electrical losses caused by transmission line deterioration are best measured using which of the following pieces of equipment? 1. A signal generator and a power meter 2. A signal generator and a frequency counter 3. An SWR meter and an oscilloscope 4. A frequency counter and a power meter

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43. What are the 3 main characteristics of operational amplifiers ?

• • • 44. In an RC filter, if R=1K and C=1 micro F, what is the cutoff frequency ? Give the formula. • Fc= 45. If a power supply has to deliver 10 A in a 2 ohm resistor, How much input power will be needed if the PS effiency is 50 % ? • Input Power = 46. What kind of electronic chips or ICs are an LM7805 and an LM555 ? • LM7805 = • LM555 = 47. What is the gain (in dB) of an amplifier where the output power = 60 W and the input power = 30 W ? • Gain = 48. In Automation and regulation systems, what does "PID" stand for ? • P= • I= • D= 49. Why can communication data travel further in RS485 as compared to RS232 ? 1. It uses Control transfer like in TCP/IP communication. 2. It talks on 2 wires instead of one. Signals are differentials. 3. It uses TTL signals 4. RS485 Devices use JFET chips and RS232 Devices use MFET chips. 50. If we release a ball from the top of an 80 meter high building, What will its speed be when it hits the ground ? Acceleration = 10 meters/second2. •

Velocity =

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