Friday, October 31, 2014

Operational Amplifiers - MCQs Answers

Filed under:

Answers key for  Operational Amplifiers
Below are the answers key for the Multiple Choice Questions (Quiz) in Operational Amplifiers from the book Electronic Devices and Circuit Theory 10th Edition by Robert L. Boylestad.

1. All of the above

2. single-ended input

3. double-ended (differential) input

4. double-ended output

5. common-mode operation

6. Common-mode

7. Emitters

8. Bipolar and MOSFET

9. bipolar, MOSFET, BiMOS

10. Virtually zero

11. Virtually zero

12. 1

13. –10

14. 11

15. 1

16. 50 mV

17. –1.5 V

18. –1 / RC

19. True

20. inverting amplifier

21. integrator

22. differentiator

23. Both an input offset voltage, VIO and an input offset current, IIO

24. –20 dB / decade or –6 dB / octave

25. All of the above

26. 1

27. 15 Hz

28. 5 V/ms

29. 250

30. 0.00375

31. The sum of the differential gain times the difference input voltage and the common-mode gain times the common input voltage.

32. The differential gain times twice the input signal.

33. The common-mode gain times the input signal.

34. V i1 = –V i2 = 0.50 V

35. Vi1 = –Vi2 = 0.50 V

FILL-IN-THE-BLANKS Questions

1. very high, wide

2. high, low

3. 180º

4. either an input is applied between the two input terminals or two separate signals are applied to the input terminals

5. outputs from both output terminals, which have opposite polarities

6. highly, slightly

7. single-ended

8. double-ended

9. common-mode

10. very large, very small

11. BiFET

12. CMOS

13. CMOS

14. infinite, zero, infinite

15. inverting

16. capacitor

17. V/ms

18. All of the above

19. increases, increases

20. decreases, decreases

21. None of the above

22. the input offset voltage and input offset current

23. closed-loop gain

24. average of the sum

25. Ad / Ac

26. infinite, larger

Complete List of Chapter Quiz in Electronic Devices and Circuit Theory


Published by: Froyd Wess11:38

Operational Amplifiers - MCQs

Filed under:

MCQs for Operational Amplifiers
This is the MCQs in Operational Amplifiers from the book Electronic Devices and Circuit Theory 10th Edition by Robert L. Boylestad. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam.

Multiple Choice Questions Topic Outline

  • MCQs in Differential Amplifier circuit
  • MCQs in BiFET, BiMOS, and CMOS Differential Amplifier circuit
  • MCQs in Op-Amp Basics
  • MCQs in Practical Op-Amp Circuits
  • MCQs in Op-Amp Specifications—DC Offset Parameters
  • MCQs in Op-Amp Specifications—Frequency Parameters
  • MCQs in Op-Amp Unit Specifications
  • MCQs in Differential and Common-Mode Operation

Begin and Good luck!

1. In which of the following are operational amplifiers (op-amps) used?

  • a. Oscillators
  • b. Filters
  • c. Instrumentation circuits
  • d. All of the above

2. This circuit is an example of a _____.

clip_image002

  • a. single-ended input
  • b. double-ended (differential) input
  • c. double-ended output
  • d. common-mode operation

3. This circuit is an example of a _____.

clip_image003

  • a. single-ended input
  • b. double-ended (differential) input
  • c. double-ended output
  • d. common-mode operation

4. This circuit is an example of a _____.

clip_image005

  • a. single-ended input
  • b. double-ended (differential) input
  • c. double-ended output
  • d. common-mode operation

5. This circuit is an example of a _____.

clip_image007

  • a. single-ended input
  • b. double-ended (differential) input
  • c. double-ended output
  • d. common-mode operation

6. In which of the following operations is the resulting output signal of the differential amplifier near zero?

  • a. Single-ended
  • b. Double-ended
  • c. Common-mode
  • d. None of the above

7. In the differential amplifier circuit, which of the following terminals are connected together?

  • a. Bases
  • b. Collectors
  • c. One base to another collector
  • d. Emitters

8. Which of the following circuits is referred to as a BiMOS circuit?

  • a. Bipolar and FET
  • b. Bipolar and MOSFET
  • c. Opposite-type MOSFETs
  • d. None of the above

9. An IC unit made using both _____ and _____ transistors is called a _____ circuit.

  • a. bipolar, MOSFET, BiFET
  • b. bipolar, MOSFET, BiMOS
  • c. TTL, MOSFET, TailFET

10. What is the level of the voltage between the input terminals of an op-amp?

  • a. Virtually zero
  • b. 5 V
  • c. 18 V
  • d. 22 V

11. What is the level of the current through the amplifier input(s) to ground in an op-amp?

  • a. Virtually zero
  • b. 1.7 mA
  • c. 2.8 mA
  • d. 3.3 mA

12. If Rf = R1’, the voltage gain is _____.

clip_image009

  • a. 1
  • b. –1
  • c. 10
  • d. very small

13. Calculate the overall voltage gain of the circuit if R1 = 100 and Rf = 1 kΩ.

clip_image010

  • a. –1
  • b. –10
  • c. 11
  • d. 9

14. Calculate the overall voltage gain of the circuit if R1 = 100 Ω and Rf = 1 kΩ.

clip_image012

  • a. –1
  • b. –10
  • c. 11
  • d. 9

15. What is the voltage gain of the unity follower?

  • a. 0
  • b. 1
  • c. –1
  • d. Infinity

16. Calculate the input voltage if R1 = 100 Ω, Rf = 1 kΩ, and Vout = 550 mV.

clip_image013

  • a. –50 mV
  • b. –5 mV
  • c. 550 mV
  • d. 50 mV

17. Calculate the output voltage if R1 = R2 = R3 = 100 Ω, Rf = 1 kΩ, and V1 = V2 = V3 = 50 mV.

clip_image015

  • a. –1.5 V
  • b. 1.5 V
  • c. 0.5 V
  • d. –0.5 V

18. What is the scale multiplier (factor) of a basic integrator?

  • a. R / C
  • b. C / R
  • c. –RC
  • d. –1 / RC

19. The summing amplifier contains an inverting amplifier.

  • a. True
  • b. False

20. This circuit is referred to as a(n) _____.

clip_image017

  • a. inverting amplifier
  • b. noninverting amplifier
  • c. unity follower
  • d. integrator

21. This circuit is referred to as a(n) _____.

clip_image019

  • a. inverting amplifier
  • b. noninverting amplifier
  • c. differentiator
  • d. integrator

22. This circuit is referred to as a(n) _____.

clip_image020

  • a. inverting amplifier
  • b. noninverting amplifier
  • c. differentiator
  • d.integrator

23. Which of the following circuit conditions affect(s) the output offset voltage of an op-amp?

  • a. An input offset voltage, VIO
  • b. An input offset current, IIO
  • c. Both an input offset voltage, VIO and an input offset current, IIO
  • d. None of the above

24. What is the level of the roll-off in most op-amps?

  • a. –6 dB / decade
  • b. –20 dB / octave
  • c. –6 dB / decade or –20 dB / octave
  • d. –20 dB / decade or –6 dB / octave

25. Which of the following is (are) the result of gain reduction by a feedback?

  • a. The amplifier voltage gain is a more stable and precise value.
  • b. The input impedance of the circuit is increased over that of the op-amp alone.
  • c. The output impedance is reduced over that of the op-amp alone.
  • d. All of the above

26. What is the open-loop gain of an op-amp at the gain-bandwidth product of the op-amp?

  • a. 200,000
  • b. 50,000
  • c. 200
  • d. 1

27. What is the cutoff frequency of an op-amp if the unity-gain frequency is 1.5 MHz and the open-loop gain is 100,000?

  • a. 5 Hz
  • b. 10 Hz
  • c. 15 Hz
  • d. 20 Hz

28. What is the slew rate of an op-amp if the output voltages change from 2 V to 3 V in 0.2 ms?

  • a. 5 V/ms
  • b. 3 V/ms
  • c. 2 V/ms
  • d. 1 V/ms

29. For an op-amp having a slew rate SR = 5 V/ms, what is the maximum closed-loop voltage gain that can be used when the input signal varies by 0.2 V in 10 ms?

  • a. 150
  • b. 200
  • c. 250
  • d. 300

30. Calculate the output impedance of an inverting op-amp using the 741 op-amp (ro = 75 Ω, AOL = 200 V/mV) if R1 = 100 Ω and Rf = 1 kΩ.

  • a. 0.011
  • b. 0.00375
  • c. 0.0375
  • d. 0.375

31. What is the difference output voltage of any signals applied to the input terminals?

  • a. The differential gain times the difference input voltage.
  • b. The common-mode gain times the common input voltage.
  • c. The sum of the differential gain times the difference input voltage and the common-mode gain times the common input voltage.
  • d. The difference of the differential gain times the difference input voltage and the common-mode gain times the common input voltage.

32. What is the difference voltage if the inputs are an ideal opposite signal?

  • a. The differential gain times twice the input signal.
  • b. The differential gain times the input signal.
  • c. The common-mode gain times twice the input signal.
  • d. The common-mode gain times the input signal.

33. What is the difference voltage if the inputs are an ideal in-phase signal?

  • a. The differential gain times twice the input signal.
  • b. The differential gain times the input signal.
  • c. The common-mode gain times twice the input signal.
  • d. The common-mode gain times the input signal.

34. At what input voltage level does the output voltage level become numerically equal to the value of the differential gain of the amplifier?

  • a. Vi1 = –Vi2 = 0.25 V
  • b. V i1 = –V i2 = 0.50 V
  • c. V i1 = –V i2 = 0.75 V
  • d. V i1 = –Vi2 = 1.00 V

35. At what input voltage level does the output voltage level become numerically equal to the value of the common-mode gain of the amplifier?

  • a. Vi1 = –Vi2 = 0.25 V
  • b. Vi1 = –Vi2 = 0.50 V
  • c. Vi1 = –Vi2 = 0.75 V
  • d.Vi1 = –Vi2 = 1.00 V

FILL-IN-THE-BLANKS

1. An operational amplifier is a _____ gain and _____ bandwidth differential amplifier.

  • A. very low, narrow
  • B. low, wide
  • C. medium, narrow
  • D. very high, wide

2. An operational amplifier has a _____ input impedance and a _____ output impedance.

  • A. high, low
  • B. high, high
  • C. low, low
  • D. low, high

3. The output signal of an op-amp is _____ out of phase with its input signal connected to the inverting input terminal.

  • A. 0º
  • B. 90º
  • C. 180º
  • D. 270º

4. In double-ended (differential) input operation, _____.

  • A. an input is applied between the two input terminals
  • B. two separate signals are applied to the input terminals
  • C. either an input is applied between the two input terminals or two separate signals are applied to the input terminals
  • D. None of the above

5. An input applied to either input terminal will result in _____.

  • A. outputs from both output terminals, which have opposite polarities
  • B. outputs from both output terminals, which have the same polarities
  • C. a single output from one of the output terminals
  • D. None of the above

6. In a differential connection, the signals that are opposite at the inputs are _____ amplified, and those that are common to the two inputs are _____ amplified.

  • A. slightly, slightly
  • B. slightly, highly
  • C. highly, highly
  • D. highly, slightly

7. In a differential amplifier circuit, if an input signal is applied to either input with the other input connected to ground, the operation is referred to as _____.

  • A. double-ended
  • B. single-ended
  • C. common-mode
  • D. All of the above

8. If two opposite-polarity input signals are applied, the operation is referred to as _____.

  • A. double-ended
  • B. single-ended
  • C. common-mode
  • D. All of the above

9. If the same input is applied to both inputs, the operation is called _____.

  • A. double-ended
  • B. single-ended
  • C. common-mode
  • D. All of the above

10. The main feature of the differential amplifier is the _____ gain when opposite signals are applied to the inputs as compared to the _____ gain resulting from common inputs.

  • A. very large, large
  • B. very small, large
  • C. very small, very large
  • D. very large, very small

11. An IC unit containing a differential amplifier built using both bipolar and FET transistors is referred to as a _____ circuit.

  • A. CMOS
  • B. BiFET
  • C. BiMOS
  • D. None of the above

12. An IC unit containing a differential amplifier built using opposite-type MOSFET transistors is referred to as a _____ circuit.

  • A. CMOS
  • B. BiFET
  • C. BiMOS
  • D. None of the above

13. A _____ differential amplifier is particularly well suited for battery operation due to its low power consumption.

  • A. BiFET
  • B. BiMOS
  • C. CMOS
  • D. BJT

14. An ideal op-amp circuit has _____input impedance, _____ output impedance, and _____ voltage gain.

  • A. zero, infinite, infinite
  • B. infinite, zero, zero
  • C. zero, zero, infinite
  • D. infinite, zero, infinite

15. The _____ amplifier is the most widely used constant-gain amplifier circuit.

  • A. inverting
  • B. noninverting
  • C. differential
  • D. None of the above

16. The feedback component of an integrator is a(n) _____.

  • A. resistor
  • B. capacitor
  • C. inductor
  • D. diode

17. _____ is the unit for the slew rate, SR.

  • A. V/ms
  • B. ms/V
  • C. V
  • D. V/s

18. The maximum frequency at which an op-amp may operate depends on the _____.

  • A. bandwidth (BW)
  • B. slew rate (SR)
  • C. unity-gain bandwidth
  • D. All of the above

19. As the supply voltage increases, the voltage gain of the circuit _____ and the power consumption _____.

  • A. increases, increases
  • B. increases, decreases
  • C. decreases, decreases
  • D. decreases, increases

20. As the frequency increases, the input impedance of an op-amp _____ and the output impedance _____.

  • A. increases, increases
  • B. increases, decreases
  • C. decreases, decreases
  • D. decreases, increases

21. Inverting amplifier connection is more widely used because it has _____.

  • A. higher gain
  • B. better frequency stability
  • C. unit gain
  • D. None of the above

22. The output offset voltage is determined by _____.

  • A. the input offset voltage and input offset current
  • B. the closed-loop gain
  • C. both the input offset voltage and the closed-loop gain
  • D. None of the above

23. The ratio of the unity-gain frequency to the cutoff frequency is numerically equal to the level of _____.

  • A. CMRR
  • B. common-mode gain
  • C. closed-loop gain
  • D. open-loop gain

24. When both input signals are the same, a common signal element due to the two inputs can be defined as the _____ of the two signals.

  • A. difference
  • B. sum
  • C. average of the sum
  • D. product

25. The common-mode rejection ratio (CMRR) is defined by _____.

  • A. Ad / Ac
  • B. Ac / Ad
  • C. Ad × Ac
  • D. Ad + Ac

26. Ideally, the value of the CMRR is _____. Practically, the _____ the value of CMRR, the better the circuit operation.

  • A. zero, smaller
  • B. infinite, larger
  • C. zero, larger
  • D. infinite, smaller

Published by: Froyd Wess11:36

Wednesday, October 29, 2014

BJT and FET Frequency Response - MCQs Answers

Filed under:

Answers key for  BJT and FET Frequency Response
Below are the answers key for the Multiple Choice Questions (Quiz) in BJT and FET Frequency Response from the book Electronic Devices and Circuit Theory 10th Edition by Robert L. Boylestad.

1. 2.3

2. 2.3

3. 6

4. –13.01 dB

5. 316.228

6. 300 mW

7. 1.225 V

8. 1 mW

9. Low-frequency

10. All of the above

11. 0.50

12. 0.707

13. –3 dB

14. High

15. Low

16. High

17. 1.0

18. About 0º

19. 45º

20. 159.15 Hz

21. 63.43º

22. 2

23. 10

24. RE = 0 Ω

25. Highest

26. 238.73 Hz

27. All of the above

28. Mid

29. All of the above

30. All of the above

31. Common-base

32. clip_image010_thumb

33. 1 to 10 pF

34. 0.1 to 1 pF

35. It is composed only of odd harmonics.

FILL-IN-THE-BLANKS Questions

1. 10, e

2. less, negative

3. 10, 1

4. 600

5. sum

6. 50

7. All of the above

8. 0.707Av mid

9. increases, decreases, more

10. 6-dB

11. 20-dB

12. highest

13. mid-frequency

14. decreased

15. inverting

16. largest, smallest

17. decrease

18. lowest

19. common-base, common-emitter

20. lowest, maximum

21. significantly greater

22. –40 dB

23. decreases

24. fundamental

25. 0.33

Complete List of Chapter Quiz in Electronic Devices and Circuit Theory


Published by: Froyd Wess17:55

BJT and FET Frequency Response - MCQs

Filed under:

MCQs for BJT and FET Frequency Response
This is the MCQs in BJT and FET Frequency Response from the book Electronic Devices and Circuit Theory 10th Edition by Robert L. Boylestad. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam.

Multiple Choice Questions Topic Outline

  • MCQs in Logarithms
  • MCQs in Decibels
  • MCQs in General Frequency Considerations
  • MCQs in Low-frequency analysis - Bode Plot
  • MCQs in Low-frequency response - BJT Amplifier
  • MCQs in Low-frequency response - FET Amplifier
  • MCQs in Miller Effect Capacitance
  • MCQs in High-frequency response - BJT Amplifier
  • MCQs in High-frequency response - FET Amplifier
  • MCQs in Multistage Frequency Effects
  • MCQs in Square wave testing
  • MCQs in Computer Analysis

Begin and Good luck!

1. What is the ratio of the common logarithm of a number to its natural logarithm?

  • a. 0.435
  • b. 2
  • c. 2.3
  • d. 3.2

2. logea = _____ log10a

  • a. 2.3
  • b. 2.718
  • c. e
  • d. 1.414

3. By what factor does an audio level change if the power level changes from 4 W to 4096 W?

  • a. 2
  • b. 4
  • c. 6
  • d. 8

4. The input power to a device is 10,000 W at 1000 V. The output power is 500 W, and the output impedance is 100 Ω. Find the voltage gain in decibels.

  • a. –30.01 dB
  • b. –20.0 dB
  • c. –13.01 dB
  • d. –3.01 dB

5. What magnitude voltage gain corresponds to a decibel gain of 50?

  • a. 31.6238
  • b. 316.228
  • c. 3162.38
  • d. 31623.8

6. An amplifier rated at 30-W output is connected to a 5-Ω speaker. Calculate the input power required for full power output if the power gain is 20 dB.

  • a. 3 mW
  • b. 30 mW
  • c. 300 mW
  • d. 3 W

7. An amplifier rated at 30-W output is connected to a 5-Ω speaker. Calculate the input voltage for the rated output if the amplifier voltage gain is 20 dB.

  • a. 1.225 mV
  • b. 12.25 mV
  • c. 122.5 mV
  • d. 1.225 V

8. For audio systems, the reference level is generally accepted as

  • a. 1 mW
  • b. 1 W
  • c. 10 mW
  • d. 100 mW

9. For which of the following frequency region(s) can the coupling and bypass capacitors no longer be replaced by the short-circuit approximation?

  • a. Low-frequency
  • b. Mid-frequency
  • c. High-frequency
  • d. All of the above

10. By what other name(s) are the cut-off frequencies in a frequency response plot called?

  • a. Corner frequency
  • b. Break frequency
  • c. Half-power frequency
  • d. All of the above

11. What is the ratio of the output power to the input power at the cut-off frequencies in a normalized frequency response plot?

  • a. 0.25
  • b. 0.50
  • c. 0.707
  • d. 1

12. What is the ratio of the output voltage to the input voltage at the cut-off frequencies in a normalized frequency response plot?

  • a. 0.25
  • b. 0.50
  • c. 0.707
  • d. 1

13. What is the normalized gain expressed in dB for the cut-off frequencies?

  • a. –3 dB
  • b. +3 dB
  • c. –6 dB
  • d. –20 dB

14. The ________-frequency response of a transformer-coupled system is calculated primarily by the stray capacitance between the turns of the primary and secondary windings.

  • a. Low
  • b. Mid
  • c. High

15. The larger capacitive elements of the design will determine the ________ cut-off frequency.

  • a. Low
  • b. Mid
  • c. High

16. The smaller capacitive elements of the design will determine the ________ cut-off frequencies.

  • a. Low
  • b. Mid
  • c. High

17. What is the ratio of the capacitive reactance XCS to the input resistance RI of the input RC circuit of a single-stage BJT amplifier at the low-frequency cut-off?

  • a. 0.25
  • b. 0.50
  • c. 0.75
  • d. 1.0

18. In the input RC circuit of a single-stage BJT, by how much does the base voltage lead the input voltage for frequencies much larger than the cut-off frequency in the low-frequency region?

  • a. About 0º
  • b. 45º
  • c. About 90º
  • d. None of the above

19. In the input RC circuit of a single-stage BJT, by how much does the base voltage lead the input voltage at the cut-off frequency in the low-frequency region?

  • a. About 0º
  • b. 45º
  • c. About 90º
  • d. None of the above

20. Determine the break frequency for this circuit.

clip_image002_thumb4

  • a. 15.915 Hz
  • b. 159.15 Hz
  • c. 31.85 Hz
  • d. 318.5 Hz

21. Refer to Figure 9.19. Calculate θ at 0.5f1.

  • a. 63.43º
  • b. 26.56º
  • c. 45º
  • d. Undefined

22. A change in frequency by a factor of ________ is equivalent to 1 octave.

  • a. 2
  • b. 10
  • c. 5
  • d. 20

23. A change in frequency by a factor of ________ is equivalent to 1 decade.

  • a. 2
  • b. 10
  • c. 5
  • d. 20

24. For the low-frequency response of a BJT amplifier, the maximum gain is where ________ .

  • a. RB = 0 Ω
  • b. RC = 0 Ω
  • c. RE = 0 Ω

25. Which of the low-frequency cutoffs determined by CS, CC, or CE will be the predominant factor in determining the low-frequency response for the complete system?

  • a. Lowest
  • b. Middle
  • c. Highest
  • d. None of the above

26. Determine the lower cut-off frequency of this network.

  • a. 15.8 Hz
  • b. 46.13 Hz
  • c. 238.73 Hz
  • d. 1575.8 Hz

27. Which of the following elements is (are) important in determining the gain of the system in the high-frequency region?

  • a. Interelectrode capacitances
  • b. Wiring capacitances
  • c. Miller effect capacitance
  • d. All of the above

28. In the ________-frequency region, the capacitive elements of importance are the interelectrode (between terminals) capacitances internal to the active device and the wiring capacitance between the leads of the network.

  • a. Low
  • b. Mid
  • c. High

29. Which of the following capacitors is (are) included in Ci for the high-frequency region of a BJT or FET amplifier?

  • a. Input wiring capacitance clip_image005_thumb
  • b. The transition capacitance (clip_image006_thumb)
  • c. Miller capacitance clip_image007_thumb
  • d. All of the above

30. In the hybrid clip_image008_thumb or Giacoletto model, which one of the following does rb include?

  • a. Base spreading resistance
  • b. Base contact
  • c. Base bulk
  • d. All of the above

31. Which of the following configurations does (do) not involve the Miller effect capacitance?

  • a. Common-emitter
  • b. Common-base
  • c. Common-collector
  • d. All of the above

32. A 3-dB drop in hfe will occur at a frequency defined by ________.

  • a. clip_image009_thumb
  • b. clip_image010_thumb
  • c. 1
  • d. 2

33. What is the range of the capacitors Cgs and Cgd?

  • a. 1 to 10 pF
  • b. 1 to 10 nF
  • c. 1 to 10 F
  • d. 1 to 10 F

34. What is the range of the capacitor Cds?

  • a. 0.01 to 0.1 pF
  • b. 0.1 to 1 pF
  • c. 0.1 to 1 nF
  • d. 0.1 to 1 F

35. Which of the following statements is true for a square-wave signal?

  • a. It is composed of both even and odd harmonics.
  • b. It is composed only of odd harmonics.
  • c. It is composed only of even harmonics.
  • d. The harmonics waveforms are also square waves.

FILL-IN-THE-BLANKS

1. Logarithms taken to the base _____ are referred to as common logarithms, while logarithms taken to the base _____ are referred to as natural logarithms.

  • A. 10, e
  • B e, 10
  • C. 5, e
  • D. 10, 5

2. The logarithm of a number _____ than 1 is always _____.

  • A. greater, negative
  • B. less, positive
  • C. less, negative
  • D. None of the above

3. The decibel (dB) is defined such that _____ decibel(s) = _____ bel(s).

  • A. 1, 10
  • B. 10, 1
  • C. 1, 1
  • D. 10, 10

4. The resistance associated with the 1-mW power level is _____ , chosen because it is the characteristic impedance of audio transmission lines.

  • A. 100
  • B. 250
  • C. 400
  • D. 600

5. The decibel gain of a cascaded system is the _____ of the decibel gains of each stage.

  • A. sum
  • B. difference
  • C. product
  • D. quotient

6. Voltage gains of _____ dB or higher should immediately be recognized as being quite high.

  • A. 3
  • B. 6
  • C. 20
  • D. 50

7. For the RC-coupled amplifier, the drop in gain at low frequencies is due to the increasing reactance of _____.

  • A. CC
  • B. Cs
  • C. CE
  • D. All of the above

8. To fix the frequency boundaries of relatively high gain, _____ was chosen to be the gain at the cut-off levels.

  • A. 0.5Av mid
  • B. 0.707Av mid
  • C. Av low
  • D. 0.5Av high

9. In the input RC circuit of a single-stage BJT or FET amplifier, as the frequency _____, the capacitive reactance _____ and _____ of the input voltage appears across the output terminals.

  • A. increases, decreases, more
  • B. increases, decreases, less
  • C. increases, increases, more
  • D. decreases, decreases, less

10. A change in frequency by a factor of 2 results in a _____ change in the ratio of the normalized gain.

  • A. 3-dB
  • B. 6-dB
  • C. 10-dB
  • D. 20-dB

11. A change in frequency by a factor of 10 results in a _____ change in the ratio of the normalized gain.

  • A. 3-dB
  • B. 6-dB
  • C. 10-dB
  • D. 20-dB

12. In the low-frequency region, the _____ low-frequency cut-off determined by CS, CC, or CE will have the greatest impact on the network.

  • A. highest
  • B. average
  • C. lowest
  • D. None of the above

13. The _____ region produces the maximum voltage gain in a single-stage BJT or FET amplifier.

  • A. low-frequency
  • B. mid-frequency
  • C. high-frequency
  • D. None of the above

14. For any inverting amplifier, the impedance capacitance will be _____ by a Miller effect capacitance sensitive to the gain of the amplifier and the interelectrode capacitance.

  • A. unaffected
  • B. increased
  • C. decreased
  • D. None of the above

15. The Miller effect is meaningful in the _____ amplifier.

  • A. inverting
  • B. noninverting
  • C. inverting/noninverting
  • D. None of the above

16. With a BJT amplifier in the high-frequency region, the capacitance Cbe is the _____ of the parasitic capacitances while Cce is the _____.

  • A. smallest, largest
  • B. largest, smallest
  • C. smallest, medium
  • D. None of the above

17. At very high frequencies, the effect of Ci is to _____ the total impedance of the parallel combination of R1, R2, R3, and Ci.

  • A. increase
  • B. maintain
  • C. decrease
  • D. None of the above

18. If the parasitic capacitors were the only elements to determine the high cut-off frequency, the _____ frequency would be the determining factor.

  • A. lowest
  • B. highest
  • C. lowest or highest
  • D. None of the above

19. The _____ configuration displays improved high-frequency characteristics over the _____ configuration.

  • A. common-collector, common-emitter
  • B. common-emitter, common-base
  • C. common-emitter, common-collector
  • D. common-base, common-emitter

20. The _____ of the upper cut-off frequencies defines a _____ possible bandwidth for a system.

  • A. highest, maximum
  • B. lowest, maximum
  • C. lowest, minimum
  • D. None of the above

21. clip_image0091_thumb is _____ than clip_image0101_thumb in a common-base configuration.

  • A. significantly smaller
  • B. smaller
  • C. significantly greater
  • D. None of the above

22. For two identical stages in cascade, the drop-off rate in the high- and low-frequency regions has increased to _____ per decade.

  • A. –3 dB
  • B. –6 dB
  • C. –20 dB
  • D. –40 dB

23. The bandwidth _____ in a multistage amplifier compared to an identical single-stage amplifier.

  • A. increases
  • B. decreases
  • C. remains the same
  • D. None of the above

24. The _____ in the Fourier series has the same frequency as the square wave itself.

  • A. fundamental
  • B. third harmonic
  • C. fifth harmonic
  • D. seventh harmonic

25. The magnitude of the third harmonic is _____ of the magnitude of the fundamental.

  • A. 1
  • B. 0.5
  • C. 0.33
  • D. 0.25

Complete List of Chapter Quiz in Electronic Devices and Circuit Theory

Check your work.


Published by: Froyd Wess17:49

Saturday, October 25, 2014

List of Multiple Choice Questions in Teach Yourself Electricity and Electronics

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Multiple Choice Questions in Teach Yourself Electricity and Electronics

You are here because you are looking for the complete set of Multiple Choice Questions in Teach Yourself Electricity and Electronics. Below are the compilation of all the test (mcqs) for each and every chapters in the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco. This includes the test exam per part and the final examination. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam.

Part 1: Direct Current
Part 2: Alternating Current
Chapter 10: MCQs in Inductance
Chapter 12: MCQs in Phase
Part 3: Basic Electronics
Chapter 24: MCQs in Amplifiers
Part 4: Advanced Electronics and Related Technology

Take the Final Exam


Published by: Froyd Wess10:46

Teach Yourself Electricity and Electronics Final Examination - Answers

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Answers key in Teach Yourself Electricity and Electronics Final Examination

Below are the answers key in Teach Yourself Electricity and Electronics Final Examination that that could test your knowledge and learning after reading the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco.

1. D. Gets larger positively.

2. D. Detecting CW.

3. D. Oscillator.

4. D. Increase the operating speed.

5. C. Kilowatt hours.

6. D. The I2R losses are lower.

7. E. An insect robot.

8. B. Superior image quality.

9. E. Collector.

10. A. A triangle. 

11. B. Gets more and more negative.

12. D. 7.72 microseconds.

13. B. A photovoltaic cell.

14. A. The connection between a computer and its monitor.

15. C. 250 mA.

16. A. An electronic calculator.

17. B. Contained in sidebands.

18. D. Placing a small variable capacitor across the crystal.

19. A. The current is the same through each one.

20. B. Protect the diodes against surge currents.

21. D. Zero reactance.

22. D. 800 μH.

23. E. Channel.

24. C. 180 degrees.

25. B. 10-3 V.

26. E. Susceptance.

27. E. Watts.

28. A. Current lags voltage by 90 degrees.

29. C. A Klystron.

30. C. At right angles to the flow of current.

31. E. 360 degrees.

32. A. Higher speed.

33. D. Keep wire leads short.

34. B. It can be easily stepped up or down in voltage.

35. B. Has a unique number of protons.

36. A. 1:16.

37. E. Nonlinear.

38. A. Current.

39. A. Carbon composition.

40. A. Machines can see at wavelengths to which human eyes are blind.

41. C. A NOT gate.

42. E. A ratio detector.

43. C. Gallium arsenide.

44. C. The dc collector voltage is positive.

45. A. A capacitor in parallel with the rectifier output.

46. D. The impedance is complex.

47. D. 100 V.

48. E. Becomes large positively.

49. E. Derivative.

50. B. Is slanted with respect to the rotational axis.

51. A. Are easily damaged by static electricity.

52. C. Ohms per meter.

53. B. Employs N-channel and P-channel FETs on a single chip.

54. B. Waveform.

55. B. Resistances in parallel.

56. D. FM.

57. A. Usually more important in transmitting systems than in receiving systems.

58. D. High and resistive.

59. C. Current lags voltage by less than 90 degrees.

60. E. 120 degrees.

61. E. Voltage.

62. A. 15 ohms.

63. D. 10 ohms.

64. C. The commutative property.

65. A. A secondary cell.

66. B. 105 ohms.

67. D. ROM.

68. B. Inversely proportional to the distance between them.

69. B. Saturation.

70. D. Large, high-gain antennas are not required.

71. E. There isn’t enough information given here to figure it out.

72. E. All of the foregoing.

73. B. Resistors.

74. E. Energy.

75. D. 12 V rms ac.

76. A. Wave X lags wave Y by 90 degrees.

77. C. Class-B.

78. C. A machine vision system.

79. C. Multivibrator.

80. B. Junction capacitance.

81. E. Very large unit.

82. D. Varactor.

83. D. Compounds.

84. C. Effective value.

85. D. Data storage capacity.

86. A. The circuit had better have a fuse or a circuit breaker.

87. B. Frequency.

88. C. The majority carriers are holes.

89. E. An electromagnet.

90. C. Ease with which a circuit passes ac.

91. C. The emitter is at signal ground.

92. D. -50 ohms.

93. C. A circuit has no reactance.

94. C. Allows a robot to tell from which direction a sound is coming.

95. B. Henry.

96. C. 12 dB.

97. D. A light-emitting diode.

98. E. To discharge the filter capacitors after the supply is shut off.

99. E. 11.1 W.

100. C. Is retained after the power is removed.

Complete List of Multiple Choice Questions from this Book


Published by: Froyd Wess10:20

Teach Yourself Electricity and Electronics Final Examination

Filed under:

Teach Yourself Electricity and Electronics Final Examination

This is the Teach Yourself Electricity and Electronics Final Examination that could test your knowledge and learning after reading the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam. This is also serve as your Pre-board exam in Engineering Electronics.

Begin the Test

1. As the frequency of ac increases in a coil, the reactance:

  • A. Gets larger negatively.
  • B. Gets smaller negatively.
  • C. Stays the same.
  • D. Gets larger positively.
  • E. Gets smaller positively.

2. A beat-frequency oscillator is useful for:

  • A. Generating FM.
  • B. Detecting FM.
  • C. Generating CW.
  • D. Detecting CW.
  • E. Any of the above.

3. A Colpitts circuit is a form of:

  • A. Amplifier.
  • B. Detector.
  • C. Modulator.
  • D. Oscillator.
  • E. Rectifier.

4. The high component density of integrated circuits acts to:

  • A. Maximize the power output.
  • B. Increase the current drain.
  • C. Increase the voltage requirements.
  • D. Increase the operating speed.
  • E. Reduce the frequency range.

5. A utility meter generally measures:

  • A. Watts.
  • B. Amperes.
  • C. Kilowatt hours.
  • D. Kilowatts.
  • E. Volt hours.

6. High voltages are better than low voltages for long-distance electric power transmission because:

  • A. The lines can better withstand lightning strokes.
  • B. The magnetic fields are weaker.
  • C. The electric fields are weaker.
  • D. The I2R losses are lower.
  • E. No. Low voltages are better.

7. A member of a fleet of robots, all under the control of a single central

computer and able to communicate only with that computer and not with

each other, is called:

  • A. An android.
  • B. An autonomous robot.
  • C. A dependent robot.
  • D. An independent robot.
  • E. An insect robot.

8. An advantage of a laser printer over a dot-matrix printer for computer

applications is:

  • A. Lower cost.
  • B. Superior image quality.
  • C. Greater bandwidth.
  • D. Lower resolution.
  • E. Better voltage regulation.

9. The output electrode of a bipolar transistor is usually the:

  • A. Grid.
  • B. Gate.
  • C. Base.
  • D. Source.
  • E. Collector.

10. The schematic symbol for an op amp is:

  • A. A triangle.
  • B. A circle.
  • C. A circle with a line through it.
  • D. A rectangle.
  • E. A D-shaped figure.

11. For a given value of capacitance, as the frequency goes down, the reactance:

  • A. Approaches zero from the negative side.
  • B. Gets more and more negative.
  • C. Approaches zero from the positive side.
  • D. Gets more and more positive.
  • E. Stays the same.

12. In a 360-Hz wave, a degree of phase represents:

  • A. 1.00 second.
  • B. 1/360 second.
  • C. 360 milliseconds.
  • D. 7.72 microseconds.
  • E. A quantity you can’t calculate from this data.

13. A device that converts visible light into dc is:

  • A. A phototransistor.
  • B. A photovoltaic cell.
  • C. An optovoltaic cell.
  • D. An optocell.
  • E. An optoisolator.

14. Which of the following is not an example of wireless?

  • A. The connection between a computer and its monitor.
  • B. A cellular telephone system.
  • C. The Global Positioning System.
  • D. A beeper.
  • E. A LEO satellite system.

15. A circuit has a battery of 3.0 V and a bulb with a resistance of 12.0 ohms. The current through the bulb is:

  • A. 36 A.
  • B. 4.0 A.
  • C. 250 mA.
  • D. 40 mA.
  • E. 36 mA.

16. A small 9-V battery might be used to provide power to:

  • A. An electronic calculator.
  • B. A personal computer.
  • C. A radio transmitter.
  • D. An electric iron.
  • E. Any of the above.

17. In an AM voice signal, the audio information is:

  • A. Exactly at the carrier frequency.
  • B. Contained in sidebands.
  • C. At harmonics of the carrier frequency.
  • D. Rectified before being impressed onto the carrier.
  • E. Detected before being impressed onto the carrier.

18. The oscillating frequency of a quartz crystal can be varied slightly by:

  • A. Changing the bias on the transistor.
  • B. Changing the voltage across the varactor.
  • C. Reversing the power supply polarity.
  • D. Placing a small variable capacitor across the crystal.
  • E. No. The frequency of a crystal cannot be changed at all.

19. When several resistances are connected in series:

  • A. The current is the same through each one.
  • B. The voltage is the same across each one.
  • C. Both A and B are true.
  • D. Neither A nor B is true.
  • E. They must all have the same value.

20. In a power supply, resistors are sometimes connected in series with the diodes in order to:

  • A. Increase the current output.
  • B. Protect the diodes against surge currents.
  • C. Help the diodes discharge.
  • D. Bleed charge from the filter capacitors.
  • E. Regulate the output voltage.

21. In a purely resistive impedance, there is:

  • A. A net capacitance.
  • B. A net inductance.
  • C. Zero resistance.
  • D. Zero reactance.
  • E. Zero conductance.

22. Two 400-μH inductors are connected in series. There is no mutual inductance. The total inductance is:

  • A. 100 μH.
  • B. 200 μH.
  • C. 400 μH.
  • D. 800 μH.
  • E. 1.6 mH.

23. The current-carrying part of a field-effect transistor, analogous to a garden hose in some ways, is called the:

  • A. Source.
  • B. Gate.
  • C. Drain.
  • D. Source-drain junction.
  • E. Channel.

24. In a rectifier diode, current flows for approximately how much of the ac cycle?

  • A. 360 degrees.
  • B. 270 degrees.
  • C. 180 degrees.
  • D. 90 degrees.
  • E. 45 degrees.

25. A millivolt is:

  • A. 103 V.
  • B. 10-3 V.
  • C. 106 V.
  • D. 10-6 V.
  • E. 10-9 V.

26. The reciprocal of reactance is called:

  • A. Impedance.
  • B. Conductance.
  • C. Resistance.
  • D. Admittance.
  • E. Susceptance.

27. Another name for joules per second is:

  • A. Volts.
  • B. Amperes.
  • C. Ohms.
  • D. Gilberts.
  • E. Watts.

28. In a pure inductance:

  • A. Current lags voltage by 90 degrees.
  • B. Current lags voltage by less than 90 degrees.
  • C. Current and voltage are in phase.
  • D. Current leads voltage by 90 degrees.
  • E. Current leads voltage by 180 degrees.

29. A form of microwave electron tube is:

  • A. A cavity resonator.
  • B. A triode.
  • C. A Klystron.
  • D. A cathode-ray tube.
  • E. None of the above.

30. Magnetic lines of flux are generally:

  • A. Parallel with the flow of electric current.
  • B. In the plane of the electric current.
  • C. At right angles to the flow of current.
  • D. At a 45 degree angle to the flow of current.
  • E. Impossible to predict as to their direction.

31. A class-A amplifier conducts during how much of the input cycle?

  • A. Less than 90 degrees.
  • B. 90–180 degrees.
  • C. 180–270 degrees.
  • D. 270–360 degrees.
  • E. 360 degrees.

32. An advantage of parallel data transfer over serial transfer is:

  • A. Higher speed.
  • B. Narrower bandwidth.
  • C. Lower frequency.
  • D. Higher power.
  • E. Better signal-to-noise ratio.

33. One way to keep interelectrode capacitance to a minimum is to:

  • A. Use only electrolytic capacitors.
  • B. Avoid the use of sheet metal.
  • C. Use batteries as the source of power.
  • D. Keep wire leads short.
  • E. Use air-core transformers.

34. One advantage of ac (compared with dc) as a source of utility power is that:

  • A. It can be used at safer voltage levels.
  • B. It can be easily stepped up or down in voltage.
  • C. There is lower transmission line loss.
  • D. The waveshape can be varied easily.
  • E. Higher voltages can be used.

35. An element of matter:

  • A. Is a good conductor.
  • B. Has a unique number of protons.
  • C. Is an insulator.
  • D. Makes a good electronic component.
  • E. Can be fabricated onto an IC chip.

36. A transformer quadruples the ac voltage. The primary-to-secondary impedance ratio is therefore:

  • A. 1:16.
  • B. 1:4.
  • C. 1:1.
  • D. 4:1.
  • E. 16:1.

37. Frequency multiplication is possible with a semiconductor diode because the diode is:

  • A. Amplifying.
  • B. Detecting.
  • C. Forward-biased.
  • D. Reverse-biased.
  • E. Nonlinear.

38. An ammeter measures:

  • A. Current.
  • B. Voltage.
  • C. Resistance.
  • D. Power.
  • E. Energy.

39. A good type of resistor to use in a radio amplifier is:

  • A. Carbon composition.
  • B. Wirewound.
  • C. Silver mica.
  • D. Reactive.
  • E. Tantalum.

40. An advantage of machine vision over human vision is the fact that:

  • A. Machines can see at wavelengths to which human eyes are blind.
  • B. Machine vision systems have equal sensitivity at all wavelengths.
  • C. Machine vision can measure pressure.
  • D. Machine vision engineers need not take image resolution into account.
  • E. Machine vision engineers need not take sensitivity into account.

41. A logic circuit has an output 0 when the input is 1, and vice versa. This is:

  • A. A NOR gate.
  • B. An AND gate.
  • C. A NOT gate.
  • D. An XOR gate.
  • E. An XNOR gate.

42. A type of FM detector that has its limiter built in is:

  • A. A balanced modulator.
  • B. A beat-frequency oscillator.
  • C. An envelope detector.
  • D. A product detector.
  • E. A ratio detector.

43. Which of the following materials is/are commonly used as a semiconductor?

  • A. Silver-mica.
  • B. Ferrite.
  • C. Gallium arsenide.
  • D. Tantalum.
  • E. All of the above.

44. In an NPN bipolar transistor circuit:

  • A. The dc collector voltage is negative.
  • B. The output is taken from the base.
  • C. The dc collector voltage is positive.
  • D. The output is taken from the drain.
  • E. Negative feedback must be used.

45. A simple power supply filter can be made using:

  • A. A capacitor in parallel with the rectifier output.
  • B. A resistor in parallel with the rectifier output.
  • C. An inductor in parallel with the rectifier output.
  • D. A capacitor in series with the rectifier output.
  • E. A resistor in series with the rectifier output.

46. If an ac admittance contains finite, nonzero resistance and finite, nonzero susceptance:

  • A. The impedance is a pure resistance.
  • B. The impedance is zero.
  • C. The resistance is zero.
  • D. The impedance is complex.
  • E. No. An ac admittance cannot contain susceptance.

47. Three resistances are in parallel, with values of 100, 200, and 300 ohms. The current through the 200-ohm resistor is 500 mA. What is the voltage across the whole combination?

  • A. There isn’t enough information to figure it out.
  • B. 400 V.
  • C. 400 mV.
  • D. 100 V.
  • E. 100 mV.

48. As the frequency of ac increases, the reactance of an inductor:

  • A. Remains constant.
  • B. Becomes small positively.
  • C. Becomes small negatively.
  • D. Becomes large negatively.
  • E. Becomes large positively.

49. The rate of change in a quantity is called the:

  • A. Effective value.
  • B. Instantaneous value.
  • C. Average value.
  • D. Peak value.
  • E. Derivative.

50. The axis of the geomagnetic field:

  • A. Corresponds exactly with the rotational axis.
  • B. Is slanted with respect to the rotational axis.
  • C. Is perpendicular to the rotational axis.
  • D. Runs parallel to lines of latitude.
  • E. Is circular in shape.

51. One of the main shortcomings of MOSFETs is that they:

  • A. Are easily damaged by static electricity.
  • B. Require high voltages.
  • C. Consume large amounts of current.
  • D. Have very low gain.
  • E. Do not have good sensitivity.

52. Resistivity of wire can be specified in:

  • A. Volts per ohm.
  • B. Ohms per volt.
  • C. Ohms per meter.
  • D. Amperes per ohm.
  • E. Ohms per ampere.

53. A complementary-metal-oxide-semiconductor (CMOS) IC:

  • A. Employs diodes and NPN transistors on a single chip.
  • B. Employs N-channel and P-channel FETs on a single chip.
  • C. Uses two chips connected together in a special way.
  • D. Uses resistors and PNP transistors on a single chip.
  • E. Consists of metal oxide sandwiched between two layers of P-type material.

54. A piano sounds different than a saxophone, even if the notes are at the same frequency, because of a difference in:

  • A. Bias.
  • B. Waveform.
  • C. Voltage.
  • D. Current.
  • E. The way you imagine it.

55. Inductances in parallel, assuming there is no mutual inductance, add up like:

  • A. Resistances in series.
  • B. Resistances in parallel.
  • C. Capacitances in parallel.
  • D. Batteries in parallel.
  • E. No other type of electrical component.

56. A reactance modulator produces:

  • A. CW.
  • B. AM.
  • C. SSB.
  • D. FM.
  • E. PCM.

57. Antenna efficiency is:

  • A. Usually more important in transmitting systems than in receiving systems.
  • B. The difference between the input and output power.
  • C. A direct function of the noise in a transmitting system.
  • D. The proportion of input power that gets converted into heat.
  • E. Highest when the transmitter final amplifier is maximally efficient.

58. In a parallel-resonant LC circuit, the impedance is:

  • A. Low and reactive.
  • B. High and reactive.
  • C. Low and resistive.
  • D. High and resistive.
  • E. Any of the above.

59. In a resistance/inductance (RL) series circuit:

  • A. Current lags voltage by 180 degrees.
  • B. Current lags voltage by 90 degrees.
  • C. Current lags voltage by less than 90 degrees.
  • D. Current and voltage are in phase.
  • E. Current leads voltage by 90 degrees.

60. In three-phase ac, the difference in phase between any two waves is:

  • A. 30 degrees.
  • B. 45 degrees.
  • C. 60 degrees.
  • D. 90 degrees.
  • E. 120 degrees.

61. Electrostatic forces can be measured to directly indicate:

  • A. Power.
  • B. Frequency.
  • C. Current.
  • D. Resistance.
  • E. Voltage.

62. A circuit has a complex impedance of 9 + j12. The absolute-value impedance is:

  • A. 15 ohms.
  • B. 9 ohms.
  • C. 12 ohms.
  • D. 21 ohms.
  • E. Impossible to calculate from this data.

63. Three resistors, each of 30 ohms, are connected in parallel. The net resistance is:

  • A. 90 ohms.
  • B. 60 ohms.
  • C. 33 ohms.
  • D. 10 ohms.
  • E. Impossible to determine from the data given.

64. The logical statement X + Y = Y + X depicts:

  • A. The distributive property.
  • B. The associative property.
  • C. The commutative property.
  • D. The de Morgan theorem.
  • E. The behavior of a NOR gate.

65. A cell that can be recharged, and therefore used again and again, is called:

  • A. A secondary cell.
  • B. A multiple-use cell.
  • C. A primary cell.
  • D. A tertiary cell.
  • E. A battery.

66. A resistor has a positive temperature coefficient of 1.00 percent per degree C.If its value is 100 ohms at 20 degrees C, what is its value at 25 degrees C?

  • A. 100 ohms.
  • B. 105 ohms.
  • C. 95 ohms.
  • D. 125 ohms.
  • E. It can’t be calculated from this data.

67. A memory that can be easily accessed, but not written over, is called:

  • A. RAM.
  • B. PRAM.
  • C. CMOS.
  • D. ROM.
  • E. CROM.

68. The capacitance between two parallel sheets of metal is:

  • A. Directly proportional to the distance between them.
  • B. Inversely proportional to the distance between them.
  • C. Not dependent on the distance between them.
  • D. Inversely proportional to their surface area.
  • E. Negligible unless the sheets are both gigantic.

69. The forward base bias in a transistor is increased until the collector current levels off. This condition is:

  • A. Cutoff.
  • B. Saturation.
  • C. Pinchoff.
  • D. Forward breakover.
  • E. Avalanche.

70. An advantage of a LEO communications satellite system over a geostationary communications satellite is the fact that:

  • A. The bandwidth is greater.
  • B. The image resolution is superior.
  • C. The satellites never change their position in the sky.
  • D. Large, high-gain antennas are not required.
  • E. The satellites orbit at higher altitudes.

71. A coil has 20 mH of inductance. What is the inductive reactance?

  • A. 20 ohms.
  • B. 0.05 ohms.
  • C. 50 ohms.
  • D. 20k ohms.
  • E. There isn’t enough information given here to figure it out.

72. What is an advantage of digital signal processing (DSP)?

  • A. Improved signal-to-noise ratio.
  • B. Enhanced fidelity.
  • C. Improved intelligibility.
  • D. Relative immunity to atmospheric noise.
  • E. All of the foregoing.

73. A dc voltage-divider network is made using:

  • A. Inductors.
  • B. Resistors.
  • C. Capacitors.
  • D. Bipolar transistors.
  • E. FETs.

74. The electron volt is a unit of:

  • A. Voltage.
  • B. Current.
  • C. Power.
  • D. Electric field strength.
  • E. Energy.

75. A transformer has a primary-to-secondary turns ratio of 10:1. The input is 120V rms ac. The output is:

  • A. 12 kV rms ac.
  • B. 1.2 kV rms ac.
  • C. 120 V rms ac.
  • D. 12 V rms ac.
  • E. 1.2 V rms ac.

76. Wave X leads wave Y by 270 degrees. This would be better expressed by saying that:

  • A. Wave X lags wave Y by 90 degrees.
  • B. Wave X lags wave Y by 180 degrees.
  • C. Wave X lags wave Y by 270 degrees.
  • D. Waves X and Y are out of phase.
  • E. Waves X and Y are in phase.

77. Which type of amplifier circuit has the transistor or FET biased exactly at cutoff or pinchoff when there is no signal input?

  • A. Class-A.
  • B. Class-AB.
  • C. Class-B.
  • D. Class-C.
  • E. Class-D.

78. The term resolution might apply to:

  • A. A hi-fi amplifier system.
  • B. A power supply.
  • C. A machine vision system.
  • D. An NPN bipolar transistor.
  • E. An electrolytic capacitor.

79. An audio oscillator that uses two amplifiers in cascade, with positive feedback from the output of the second stage to the input of the first stage, is known as a:

  • A. Colpitts circuit.
  • B. Hartley circuit.
  • C. Multivibrator.
  • D. VCO.
  • E. Clapp circuit.

80. The main factor that limits the frequency at which a P-N junction will rectify is the:

  • A. PIV rating.
  • B. Junction capacitance.
  • C. Junction resistance.
  • D. Junction inductance.
  • E. Reverse bias current.

81. The henry is a:

  • A. Very small unit.
  • B. Unit of capacitive reactance.
  • C. Measure of transistor gain.
  • D. Unit of phase.
  • E. Very large unit.

82. A diode that can be used as a variable capacitance is a:

  • A. GaAsFET.
  • B. Silicon rectifier.
  • C. Point-contact diode.
  • D. Varactor.
  • E. Germanium detector.

83. Elements can join together to form:

  • A. Ions.
  • B. Isotopes.
  • C. Nuclei.
  • D. Compounds.
  • E. Majority carriers.

84. The rms value for an ac wave is also sometimes called the:

  • A. Absolute value.
  • B. Direct-current value.
  • C. Effective value.
  • D. Equivalent value.
  • E. Reactive value.

85. The gigabyte is a unit commonly used as a measure of:

  • A. Data access time.
  • B. Data frequency.
  • C. Data transfer speed.
  • D. Data storage capacity.
  • E. Data communications accuracy.

86. In a parallel combination of light bulbs, if one bulb socket totally shorts out:

  • A. The circuit had better have a fuse or a circuit breaker.
  • B. The other bulbs will burn out.
  • C. The other bulbs will dim slightly, but stay lit.
  • D. The current drawn from the source will decrease.
  • E. None of the above.

87. A common lab multimeter cannot measure:

  • A. Current.
  • B. Frequency.
  • C. Voltage.
  • D. Resistance.
  • E. It can measure any of the above.

88. In a P-channel JFET:

  • A. The drain is positive with respect to the source.
  • B. The gate must be grounded.
  • C. The majority carriers are holes.
  • D. The source receives the input signal.
  • E. All of the above are true.

89. If you place a bar of iron inside a cylindrical coil of wire, and then run dc through the wire, you have:

  • A. A rheostat.
  • B. A permanent magnet.
  • C. A flux meter.
  • D. An electric generator.
  • E. An electromagnet.

90. Admittance is a quantity expressing:

  • A. Opposition to dc.
  • B. Opposition to audio signals.
  • C. Ease with which a circuit passes ac.
  • D. The ratio of capacitance to inductance.
  • E. The ratio of reactance to resistance.

91. In a common-emitter bipolar-transistor circuit:

  • A. The collector is at signal ground.
  • B. The output is taken from the base.
  • C. The emitter is at signal ground.
  • D. The bases of two transistors are connected together.
  • E. The output is taken from the emitter.

92. In a certain resistance-capacitance (RC) circuit, the current leads the voltage by 45 degrees. The resistance is 50 ohms. The capacitive reactance is:

  • A. 25 ohms.
  • B. -25 ohms.
  • C. 50 ohms.
  • D. -50 ohms.
  • E. Impossible to determine from this information.

93. The VA power is equal to the true power only when:

  • A. A circuit has no resistance.
  • B. A circuit has no impedance.
  • C. A circuit has no reactance.
  • D. The complex impedance is high.
  • E. The phase angle is 45 degrees.

94. Binaural machine hearing can be advantageous over monaural machine hearing because the binaural scheme:

  • A. Allows a robot to measure the frequency of a sound.
  • B. Allows a robot to determine the amplitude of a sound.
  • C. Allows a robot to tell from which direction a sound is coming.
  • D. Allows a robot to ascertain the waveform of a sound.
  • E. Allows a robot to interpret spoken commands.

95. The standard unit of inductance is the:

  • A. Farad.
  • B. Henry.
  • C. Gilbert.
  • D. Gauss.
  • E. Tesla.

96. The output of an amplifier circuit is 20 V and the input is 5.0 V. The input and output impedances are identical. The circuit thus has a gain of:

  • A. 4 dB.
  • B. 6 dB.
  • C. 12 dB.
  • D. -4 dB.
  • E. -6 dB.

97. An example of a device that converts electrical energy into visible radiant energy is:

  • A. A photocell.
  • B. A phototransistor.
  • C. A photovoltaic cell.
  • D. A light-emitting diode.
  • E. A speaker.

98. What is the function of bleeder resistors in a power supply?

  • A. To regulate the current.
  • B. To regulate the voltage.
  • C. To protect the rectifier diodes against electromagnetic interference.
  • D. To protect the rectifier diodes against current surges.
  • E. To discharge the filter capacitors after the supply is shut off.

99. A resistor of 100 ohms carries 333 mA dc. The power dissipated by that resistor is:

  • A. 300 mW.
  • B. 3.33 W.
  • C. 33.3 W.
  • D. 3.33 W.
  • E. 11.1 W.

100. The data in nonvolatile memory:

  • A. Is stored on magnetic disks.
  • B. Consists of analog waveforms.
  • C. Is retained after the power is removed.
  • D. Must pass through a modem before it can be understood by the CPU.
  • E. Cannot be used by a microprocessor.

Complete List of Multiple Choice Questions from this Book

Check your work.


Published by: Froyd Wess10:15