PinoyBIX Engineering Problem Solving and Reference

This is the Textbook Assignment: Chapter 1, "Circuit Measurement" from the Module 3 — Introduction to Circuit Protection, Control, and Measurement in Navy Electricity and Electronics Training Series (NEETS) . If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. Circuit measurement is used for which of the following purposes?

• A. To find the weight of a circuit
• B. To increase the power used in a circuit
• C. To discover the length and width of a circuit
• D. To determine the reason a circuit is not functioning properly

2. An in-circuit meter is used for which of the following purposes?

• A. To reduce circuit losses
• B. To monitor circuit operation
• C. To control power to a circuit
• D. To prevent circuit overload conditions

3. Out-of-circuit meters have which of the following advantages over in circuit meters?

• A. They can be used on more than one device
• B. They are lighter weight
• C. They are more rugged
• D. All of the above

7. The d'Arsonval meter movement is based on which of the following principles?

• A. Moving vane
• B. Electrostatic
• C. Electrodynamic
• D. Permanent-magnet moving-coil

8. Current through a meter results in the pointer. In d'Arsonval meter movement, what force produces this deflection?

• A. Thermocouple action
• B. Electrostatic repulsion
• C. Mechanical spring tension
• D. The interaction of magnetic fields

9. The hairsprings in a d'Arsonval meter movement perform which of the following functions?

• A. They keep the pointer in the position of the last indication when current is removed
• B. They aid the movement of the pointer when there is current through the meter
• C. They make electrical connections to the meter movement
• D. All of the above

12. What device allows a d'Arsonval meter movement to measure ac by converting ac to pulsating dc?

• A. A pulsator
• B. A modulator
• C. A rectifier
• D. A converter

13. What is meant by the term "meter damping"?

• A. Moistening the felt pads
• B. Smoothing the oscillations of the pointer
• C. Preventing excessive current through the coil
• D. Compensating for electromagnetic induced interference

14. Which of the following methods is used to dampen a meter?

• A. Mount the meter in a mu-metal case
• B. Install a fuse in one of the input leads
• C. Incorporate an airtight chamber containing a van
• D. Provide a fluid reservoir and sponge arrangement next to the pads

15. A d'Arsonval meter movement reacts to which of the following values of voltage?

• A. Peak
• B. Average
• C. Effective
• D. Peak-to-peak

16. What value of ac is indicated by a meter scale?

• A. Peak
• B. Average
• C. Effective
• D. Peak-to-peak

17. Which of the following meter movements will measure either ac or dc without the use of a rectifier?

• A. GMS
• B. d'Arsonval
• C. Electrostatic
• D. Electrodynamic

18. What electrical property is reacted to by the electrodynamic, d'Arsonval, moving vane, and thermocouple meter movements?

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

19. What electrical property is measured by an ammeter?

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

20. How are ammeters connected in an electrical circuit?

• A. In series with the load
• B. In parallel with the load
• C. In accordance with Lenz's Law
• D. In series-parallel with the load

21. How does an ammeter affect the circuit being measured?

• A. It acts as a resistances in series and lowers the circuit current
• B. It acts as a resistance in series and raises the circuit current
• C. It acts as a resistance in parallel and lowers the circuit current
• D. It acts as a resistance in parallel and raises the circuit current

22. How is the effect that an ammeter produces in a circuit kept to a minimum?

• A. By using a large resistor in series with the ammeter
• B. By using a large capacitor in parallel with the ammeter
• C. By ensuring that the meter resistance is low compared to circuit resistance
• D. By ensuring that the meter resistance is high compared to circuit resistance

23. The ammeter with the greatest sensitivity has which of the following characteristics?

• A. The lowest amount of current for fullscale deflection indication
• B. The highest amount of current for fullscale deflection indication
• C. A low ratio of internal resistance to full-scale deflection indication
• D. A high ratio of internal resistance to full-scale deflection indication

24. Ammeters measure various ranges through the addition of which of the following components?

• A. Shunt resistors in series with the meter movement
• B. Shunt resistors in parallel with the meter movement
• C. Capacitors in series with the meter movement
• D. Capacitors in parallel with the meter movement

25. What range of an ammeter should you use for an initial measurement?

• A. The lowest range
• B. The highest range
• C. The mid-scale range
• D. None of these

26. What portion of the ammeter scale should be used to take a final reading?

• A. The upper half
• B. The lower half
• C. The mid-scale portion
• D. Anywhere on the meter face

27. When, if ever, can you use a dc ammeter to measure ac values?

• A. When the ac is high frequency
• B. For low values
• C. Always
• D. Never

28. Which of the following safety precautions should be observed prior to connecting an ammeter into a circuit?

• A. Switch to the highest range
• B. Observe proper dc polarity
• C. Deenergize the circuit
• D. All of the above

29. What electrical property is measured by a voltmeter?

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

30. A voltmeter should be connected in an electrical circuit in what manner?

• A. In series with the load
• B. In parallel with the load
• C. In accordance with Lenz's Law
• D. In series-parallel with the load

31. A voltmeter has an effect on the circuit being measured; what is this effect called?

• A. Loading
• B. Damping
• C. Rectification
• D. Eddy-current drag

32. To keep the effect of a voltmeter on a circuit to a minimum, the internal resistance of the voltmeter must have which of the following relationships to the circuit load?

• A. Equal to
• B. Lower than
• C. Higher than
• D. In proportion to

33. Which of the following types of meters can be made from a current sensitive meter movement?

• A. Ammeter
• B. Ohmmeter
• C. Voltmeter
• D. Each of the above

34. A voltmeter has a high sensitivity when it has which of the following characteristics?

• A. Low deflection indication
• B. High deflection indication
• C. Low ratio of internal resistance to full scale deflection indication
• D. High ratio of internal resistance to full-scale deflection indication

35. Which of the following configurations extends the range of a voltmeter?

• A. A resistor in series with the meter movement
• B. A resistor in parallel with the meter movement
• C. A capacitor in series with the meter movement
• D. A capacitor in parallel with the meter movement

36. What voltmeter range should be used for initial measurements?

• A. The lowest
• B. The highest
• C. The mid-scale
• D. None of these

37. The electrostatic meter movement reacts to which of the following electrical properties?

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

38. Electrostatic meter movements are used to measure which of the following current/voltage values?

• A. Low voltage
• B. Low current
• C. High voltage
• D. High current

39. Which of the following safety precautions should be observed when a voltmeter is used?

• A. Deenergize the circuit before connecting the meter
• B. Start with the lowest range of the meter
• C. Connect the meter in series with the circuit
• D. All of the above

40. What electrical property is measured with an ohmmeter?

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

41. An ohmmeter is used to check for which of the following conditions?

• A. Continuity
• B. Overheating
• C. Overcurrent
• D. Undercurrent

42. How should an ohmmeter be connected in an electrical circuit?

• A. In series with the load
• B. In parallel with the load
• C. In parallel with the source
• D. In series-parallel with the load

43. An ohmmeter can measure different ranges because of the use of which of the following components?

• A. Range coils
• B. Range resistors
• C. Range capacitors
• D. Range potentiometers

44. What area of an ohmmeter scale should be used when a measurement is taken?

• A. Upper half
• B. Lower half
• C. Mid-scale portion
• D. Anywhere on the meter face

45. Ohmmeter are classified by type. What are the two types of ohmmeters?

• A. Series and shunt
• B. Normal and reverse
• C. Full- and half-scale
• D. None of these

46. What is the most obvious differences in the two types of ohmmeters?

• A. The ranges of the meters
• B. The scales of the meters
• C. The power sources of the meters
• D. The size of the test leads of the meters

47. Which of the following safety precautions should be observed when an ohmmeter is used?

• A. Always start with the highest scale of the meter
• B. Deenergize the circuit before connecting the meter
• C. Observe proper polarity
• D. All of the above

48. Meggers (megohmmeters) are used to measure which of the following quantities?

• A. Low voltage
• B. High voltage
• C. Low resistance
• D. High resistance

49. When a megger is used to check the insulation of a wire, which of the following indications should be considered normal?

• A. ∞
• B. 0
• C. 500 V
• D. 1000 V

50. Which of the following safety precautions should be observed when a megger is used?

• A. Do not use a dc megger to measure circuits that are powered by ac
• B. Always start with the highest scale selection of the meter
• C. Do not touch the meter leads when a measurement is being taken
• D. All of the above

51. A multimeter can be used to measure which of the following electrical properties?

• A. Voltage
• B. Current
• C. Resistance
• D. Each of the above

52. The function switch on a multimeter does NOT perform which of the following functions?

• A. Selection of the meter range
• B. Determination of the proper scale
• C. Selection of ac or dc capability
• D. Changing of the multimeter from an ammeter to a voltmeter

53. One of the problems encountered in building a multimeter is that the meter movement gives different readings for the same values of ac and dc. Which of the following features of a multimeter will solve this problem?

• A. A rectifier
• B. An ac/dc switch
• C. Separate scales for ac and dc
• D. A mirror on the face of the meter

54. Why is there a mirror on the face of a multimeter?

• A. To illuminate the meter face
• B. To aid in reducing parallax error
• C. To reduce the friction between the pointer and the meter face
• D. To compensate for the difference in ac and dc measurements

55. If the mirror on the face of a multimeter is used properly, where will the image of the pointer appear?

• A. Hidden behind the pointer
• B. Barely visible on either side of the pointer
• C. Clearly visible to the left of the pointer
• D. Clearly visible to the right of the pointer

56. Which of the following safety precautions does NOT apply to a multimeter?

• A. Observe proper dc polarity when measuring dc
• B. Deenergize the circuit before connecting the meter
• C. Be sure the meter is switched to ac for ac measurements
• D. Never apply power to the circuit when measuring voltage with the meter

57. If a multimeter has no OFF position, and it is returned to storage, on which of the following positions should the meter be set?

• A. +dc; highest voltage range
• B. -dc; higher resistance range
• C. Ac; highest voltage range
• D. Ac; highest current range

58. When the current in a conductor is measured without the conductor being disconnected, which of the following meters could be used?

• A. Multimeter
• B. Hook-on voltameter
• C. Induction wattmeter
• D. Transformer voltmeter

59. Which of the following electrical quantities is measured by a wattmeter?

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

60. Which of the following electrical quantities is measured by a watt hour meter?

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

Check your work.

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This is the Textbook Assignment: Chapter 3, "Capacitance" from the Module 2 — Introduction to Alternating Current and Transformers in Navy Electricity and Electronics Training Series (NEETS) . If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Start Practice Exam Test Questions

Choose the letter of the best answer in each mcq.

1. Capacitance and inductance in a circuit are similar in which of the following ways?

• A. Both oppose current
• B. Both aid voltage
• C. Both cause the storage of energy
• D. Both prevent the storage of energy

2. Capacitance is defined as the property of a circuit that

• A. opposes a change in voltage
• B. aids a change in voltage
• C. opposes a change in current
• D. aids a change in current

3. A capacitor is a device that stores energy in a/an

• A. electrostatic field
• B. electromagnetic field
• C. induced field
• D. molecular field

4. Electrostatic fields have what effect on (a) free electrons, and (b) bound electrons?

• A. (a) Attracts them to the negative charges (b) Frees them from their orbits
• B. (a) Attracts them to the positive charges (b) Frees them from their orbits
• C. (a) Attracts them to the negative charges (b) Distorts their orbits
• D. (a) Attracts them to the positive charges (b) Distorts their orbits

5. The influence of a charge on an electron orbit is correctly depicted by which of the following illustrations?

6. Electrostatic lines of force radiate from a charged particle along what type of lines?

• A. Straight lines
• B. Curved lines
• C. Elliptical lines
• D. Orbital lines

9. Which of the following combinations describe(s) a simple capacitor?

• A. Two copper plates separated by an iron plate
• B. Two copper plates separated by a sheet of mica
• C. Two iron plates separated by an air gap
• D. Both B and C above

10. A capacitor that stores 6 coulombs of electrons when a potential of 2 volts is applied across its terminals has what total value of capacitance?

• A. 12 farads
• B. 8 farads
• C. 3 farads
• D. 6 farads

15. A capacitor of 0.0069 microfarad has which of the following capacitance values when measured in picofarads?

• A. 0.000069 pF
• B. 6900 pF
• C. 6.9 x 10^-9 pF
• D. Both B and C above, individually, are correct

16. Which of the following characteristics of a capacitor can be varied WITHOUT altering its capacitance?

• A. Area of the plates
• B. Thickness of the dielectric
• C. Material of the dielectric
• D. Thickness of the plates

17. Which of the following actions will increase the capacitance of a capacitor?

• A. The plates are moved closer together
• B. The plates are moved farther apart
• C. The dielectric constant is decreased
• D. Both B and C above

18. Two capacitors are identical with the exception of the material used for the dielectric. Which of the following combinations of dielectric material will cause capacitor (b) to have a larger capacitance than capacitor (a)?

• A. (a) Glass (b) Paraffin paper
• B. (a) Glycerine (b) Pure water
• C. (a) Petroleum (b) Air
• D. (a) Paraffin paper (b) Petroleum

19. Two capacitors are identical with the exception of the material used for the dielectric. Which of the following combinations of dielectric materials will cause the capacitors to have almost the same capacitance?

• A. Glass, paraffin paper
• B. Mica, petroleum
• C. Vacuum, air
• D. Petroleum, rubber

20. A capacitor is composed of two plates. Each plate has an area of 7 square inches. The plates are separated by a 2-inch thick paraffin paper dielectric. What is its capacitance?

• A. 2.76 μF
• B. 2.76 pF
• C. 5.51 μF
• D. 5.51 pF

21. The maximum voltage that can be applied to a capacitor without causing current flow through the dielectric is called

• A. breaking voltage
• B. limiting voltage
• C. conduction voltage
• D. working voltage

22. A capacitor with a working voltage of 300 volts would normally have what maximum effective voltage applied to it?

• A. 200 volts
• B. 250 volts
• C. 300 volts
• D. 350 volts

23. An ac voltage of 350 volts effective can be safely applied to a capacitor with which of the following working voltages?

• A. 550 volts
• B. 400 volts
• C. 350 volts
• D. 250 volts

24. Which, if any, of the following conditions may cause a capacitor to suffer power losses?

• A. Dielectric hysteresis
• B. Plate loading
• C. Plate heating
• D. None of these

25. Rapid reversals in the polarity of the line voltage applied to a capacitor will cause what type of capacitor power loss?

• A. Dielectric-leakage
• B. Dielectric-hysteresis
• C. Plate-loading
• D. Plate-leakage

26. What type of dielectric is LEAST sensitive to power dielectric-hysteresis losses?

• A. Pure water
• B. Air
• C. Vacuum
• D. Mica

27. As the current through a capacitor increases, which of the following types of capacitor losses will increase?

• A. Dielectric-hysteresis
• B. Dielectric-leakage
• C. Plate-leakage
• D. Plate-breakdown

49. A circuit contains four parallel connected capacitors of 33 μF each. What is the total capacitance of the circuit?

• A. 8.3 μF
• B. 33.0 μF
• C. 183.0 μF
• D. 132.0 μF

50. A circuit contains two series-connected capacitors of 15 μF, and 1500 pF. What is the total capacitance of the circuit?

• A. 0.0015 pF
• B. 150.0 pF
• C. 0.0015 μF
• D. 0.1500 μF

51. A circuit contains two 10 μF capacitors wired together in a parallel configuration. The two parallel-wired capacitors are wired in series with a 20 μF capacitor and a 20 Kilo-ohm resistor. Which of the following expresses the RC time constant for this circuit?

• A. 0.2 sec
• B. 2 sec
• C. 20,000 sec
• D. Both B and C above

52. How are fixed capacitors classified?

• A. By their plate size
• B. By their dielectric materials
• C. By the thickness of their dielectric materials
• D. By the thickness of their conductors

53. Which of the following types of capacitors are referred to as self-healing?

• A. Ceramic
• B. Paper
• C. Oil
• D. Mica

Check your work.

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This is the Textbook Assignment: Chapter 2, "Inductance" from the Module 2 — Introduction to Alternating Current and Transformers in Navy Electricity and Electronics Training Series (NEETS) . If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. The property of inductance offers opposition to which of the following quantities?

• A. Constant current
• B. Constant voltage
• C. Changes in current
• D. Changes in voltage

2. What is the symbol for inductance?

• A. L
• B. H
• C. X_L
• D. IND

3. What is the unit of measurement for inductance?

• A. Ohm
• B. Rel
• C. Farad
• D. Henry

4. If 9 volts are induced in a conductor when the current changes by 4.5 amperes in one second, what is the total inductance of the circuit?

• A. 1.5 henries
• B. 2.0 henries
• C. 13.5 henries
• D. 40.0 henries

5. What physical property is similar to inductance?

• A. Mass
• B. Motion
• C. Velocity
• D. Inertia

6. The difference in potential across a resistor, created by current through the resistor is an example of which of the following forces?

• A. Resistive
• B. Inertia
• C. Inductive
• D. Electromotive

7. When a magnetic field moves through a stationary conductor, the electrons in orbit are affected in what manner?

• A. They are dislodged from orbit
• B. They move closer to their nucleus
• C. They move closer to other orbiting electrons
• D. They bunch up on one side of the nucleus

8. When electrons are moved in a conductor by a magnetic field, a force known by which of the following terms is created?

• A. Voltage
• B. Electromotive
• C. Potential difference
• D. All of these

9. Self-induced emf is also known as what force?

• A. magnetic force
• B. Inertial force
• C. Electromotive force
• D. Counter electromotive force

10. According to Lenz’s Law, the induced emf produced by a change in current in an inductive circuit tends to have what effect on the current?

• A. It aids a rise in current and opposes fall in current
• B. It aids a fall in current and opposes a rise in current
• C. It opposes either a rise or a fall in current
• D. It aids either a rise or fall in current

11. The direction of the induced voltage in an inductor may be found by application of which of the following rules?

• A. The left-hand rule for inductors
• B. The left-hand rule for generators
• C. The right-hand rule for conductors
• D. The right-hand rule for motors

12. The left-hand rule for generators states that the thumb of the left hand points in the direction of motion of the

• A. conductor
• B. magnetic field
• C. generator poles
• D. induced current

13. When source voltage is removed from a current-carrying conductor, a voltage will be induced in the conductor by which of the following actions?

• A. The decreasing voltage
• B. The collapsing magnetic field
• C. The reversal of current
• D. The reversing electrical field

14. The property of inductance is present in which of the following electrical circuits?

• A. An ac circuit
• B. A dc circuit
• C. A resistive circuit
• D. Each of these

15. How are inductors classified?

• A. By core type
• B. By conductor type
• C. By the number of turns
• D. By the direction of the windings on the core

16. Normally, most coils have cores composed of either air or

• A. copper
• B. carbon
• C. soft iron
• D. carbon steel

17. The hollow form of nonmagnetic material found in the center of an air core coil has what purpose?

• A. To focus the magnetic flux
• B. To support the windings
• C. To act as a low resistance path for flux
• D. To serve as a container for the core

18. Which of the following factors will NOT affect the value of inductance of a coil?

• A. Number of coil turns
• B. Diameter of the coil
• C. Conductor tensility
• D. Core materials used

19. When the number of turns is increased in a coil from 2 to 4, the total inductance will increase by a factor of

• A. eight
• B. two
• C. six
• D. four

20. Why do large diameter coils have greater inductance than smaller diameter coils, all other factors being the same?

• A. Large diameter coils have more wire and thus more flux
• B. Large diameter coils have less resistance
• C. Small diameter coils have less resistance
• D. Small diameter coils have large cemfs which oppose current flow

21. If the radius of a coil is doubled, its inductance is increased by what factor?

• A. One
• B. Two
• C. Eight
• D. Four

22. If the length of a coil is doubled while the number of turns is kept the same, this will have (a) what effect on inductance and (b) by what factor?

• A. (a) Decrease, (b) by 1/4
• B. (a) Decrease, (b) by 1/2
• C. (a) Increase, (b) by 2 times
• D. (a) Increase, (b) by 4 times

23. A soft iron core will increase inductance because it has which of the following characteristics?

• A. Low permeability and low reluctance
• B. Low permeability and high reluctance
• C. High permeability and high reluctance
• D. High permeability and low reluctance

24. An increase in the permeability of the core of a coil will increase which of the following coil characteristics?

• A. Magnetic flux
• B. Reluctance
• C. Resistance
• D. Conductance

25. If a coil is wound in layers, its inductance will be greater than that of a similar single-layer coil because of a higher

• A. permeability
• B. flux linkage
• C. reluctance
• D. conductance

26. Regardless of the method used, inductance of a coil can ONLY be increased by increasing what coil characteristic?

• A. Transconductance
• B. Reluctance
• C. Flux linkage
• D. Conductance

27. What is the symbol used to denote the basic unit of measurement for inductance?

• A. L
• B. H
• C. I
• D. F

28. What does the Greek letter Delta signify as in "DI" or "Dt"?

• A. The values are constant
• B. The values are average
• C. The values are changing
• D. The values are effective

29. An electrical circuit contains a coil. When the current varies 2.5 amperes in one second, 7.5 volts are induced in the coil. What is the value of inductance of the coil?

• A. 1 henry
• B. 2.2 henries
• C. 3.3 henries
• D. 4 henries

30. An ac electrical current varies 1.5 amperes in one second and is applied to a 10-henry coil. What is the value of the emf induced across the coil?

• A. 1.0 volt
• B. 1.5 volts
• C. 11.5 volts
• D. 15.0 volts

31. If a coil is rated at 10 henries, what is its value in (a) millihenries and (b) microhenries?

• A. (a) 10,000 mH, (b) 10,000,000 μH
• B. (a) 10,000 mH, (b) 1,000,000 μH
• C. (a) 1,000 mH, (b) 1,000,000 μH
• D. (a) 1,000 mH, (b) 100,000 μH

41. One L/R time constant is equal to the time required for the current in an inductor to reach what portion of its maximum value?

• A. 63.2%
• B. 37.8%
• C. 25.2%
• D. 12.8%

42. Maximum current will flow in an LR circuit after a minimum of how many time constants have elapsed?

• A. One
• B. Five
• C. Three
• D. Four

43. The maximum current in an LR circuit is 20 amperes. What total current will be flowing in the circuit at the end of the second time constant of the charge cycle?

• A. 20.0 amperes
• B. 17.3 amperes
• C. 12.6 amperes
• D. amperes

44. Refer to the circuit described in question 43. Circuit current will increase by what amount during the second time constant?

• A. 17.3 amperes
• B. 12.6 amperes
• C. 7.6 amperes
• D. 4.7 amperes

45. An LR circuit has a maximum current of 30 mA. At the end of the first time constant of the discharge cycle, what total current will be flowing in the circuit?

• A. 11 mA
• B. 19 mA
• C. 26 mA
• D. 28 mA

46. An LR circuit contains a 150-ohm resistor and a 2-henry coil. What is the time value of one L/R time constant?

• A. 7.5 seconds
• B. 0.75 seconds
• C. 1.33 seconds
• D. 0.0133 seconds

47. An LR circuit has a time constant of 0.05 second and an inductor with a value of 0.60 henry. What value of resistor is required?

• A. 5 ohms
• B. 12 ohms
• C. 24 ohms
• D. 64 ohms

48. An LR circuit is composed of a coil of 0.5 henry and a 10-ohm resistor. The maximum current in the circuit is 5 amperes. After the circuit is energized, how long will it take for the current to reach maximum value?

• A. 1.0 second
• B. 0.05 second
• C. 0.25 second
• D. 5.0 seconds

49. Inductors experience copper loss for what reason?

• A. Because of flux leakage in the copper core
• B. Because the reactance of an inductor is greater than the resistance of an inductor
• C. Because all inductors have resistance which dissipates power
• D. Because the inertia of the magnetic field must be overcome every time the direction of current changes

50. Copper loss of an inductor can be calculated by the use of which of the following formulas?

• A. P = I²R
• B. P = I²E
• C. P = E/R²
• D. P = I²/R

51. What term applies to the power loss in an iron core inductor due to the current induced in the core?

• A. Iron loss
• B. Heat loss
• C. Hysteresis loss
• D. Eddy-current loss

52. Power consumed by an iron core inductor in reversing the magnetic field of the core is termed as what type of loss?

• A. Iron loss
• B. Heat loss
• C. Hysteresis loss
• D. Eddy-current loss

53. When does mutual inductance occur between inductors?

• A. Whenever eddy-currents do not exist
• B. Whenever the flux of one inductor causes an emf to be induced in another inductor
• C. Whenever the effect of one inductor is aided by another inductor
• D. Whenever the effect of one inductor is opposed by another inductor

54. Mutual inductance between two coils is affected by which of the following factors?

• A. Material of the windings
• B. Physical dimensions of the coils
• C. Direction of the coil windings
• D. Hysteresis characteristics of the coils

55. The coefficient of coupling between two coils is a measure of what factor?

• A. The turns ratio of the coils
• B. The distance between the coils
• C. The relative positive of the coils
• D. The magnetic flux ratio linking the coils

56. Two coils have a coefficient of coupling of 0.7 and are rated at 12 μH and 3 μH respectively. What is their total mutual inductance?

• A. 4.2 μH
• B. 5.2 μH
• C. 7.0 μH
• D. 10.5 μH

57. An electrical circuit contains four non-coupled inductors in a series configuration. The inductors have the following values: 2 μH, 3.5 μH, 6 μH, and 1 μH. What is the total inductance (L_T) of the circuit?

• A. 45.0 μH
• B. 42.5 μH
• C. 12.5 μH
• D. 11.5 μH

58. Two inductors of 3.6 μH and 7.3 μH are wired together in series and they aid each other. The mutual inductance for the circuit is 3.6 μH. What is the total inductance (L_T) of the circuit?

• A. 17.5 μH
• B. 18.1 μH
• C. 24.8 μH
• D. 34.4 μH

59. An electrical circuit contains three non-coupled inductors of 3.3 μH, 4.5 μH, and 2.0 μH wired in parallel. What is the total inductance of the circuit?

• A. 9.8 μH
• B. 3.6 μH
• C. 0.98 μH
• D. 0.28 μH

Check your work.

---

This is the Textbook Assignment: Chapter 1, "Concepts of Alternating Current" from the Module 2 — Introduction to Alternating Current and Transformers in Navy Electricity and Electronics Training Series (NEETS) . If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. Alternating current can be defined as current that varies in

• A. amplitude and direction
• B. magnitude and phase
• C. amplitude and time
• D. time and phase

2. Before a 120-volt dc source can be used to power a 12-volt load, the voltage must be reduced. Which of the following methods can be used?

• A. A resistor placed in parallel with the load
• B. A resistor placed in series with the load
• C. A step-down transformer placed in series with load
• D. A step-down transformer placed in parallel-with the load

3. Alternating current has replaced direct current in modern transmission systems because it has which of the following advantages?

• A. Ac can be transmitted with no line loss
• B. Ac can be transmitted at higher current levels
• C. Ac can be transmitted at lower voltage levels
• D. Ac can be readily stepped up or down

4. A waveform is a graphic plot of what quantities?

• A. Current versus time
• B. Amplitude versus time
• C. Voltage versus amplitude
• D. Magnitude versus amplitude

5. Which of the following properties surrounds a current-carrying conductor?

• A. A magnetic field
• B. A repulsive force
• C. An attractive force
• D. An electrostatic field

9. Which of the following statements accurately describes the magnetic field surrounding a current-carrying conductor?

• A. It is parallel to and equal along all parts of the conductor
• B. It is parallel to and maximum at the most negative part of the conductor
• C. It is perpendicular to and equal along all parts of the conductor
• D. It is perpendicular to the conductor and maximum at the most negative point of the conductor

10. Which of the following factors determine(s) the intensity of a magnetic field surrounding a coil?

• A. The amount of current flow through the coil
• B. The type of core material
• C. The number of turns in the conductor
• D. All of these

11. When you grasp a coil in your left hand with your thumb pointing in the direction of the north pole, your fingers will be wrapped around the coil in the direction of the

• A. voltage potential
• B. magnetic field
• C. current flow
• D. south pole

12. The power consumed in a conductor in realigning the atoms which set up the magnetic field is known as what type of loss?

• A. Hysteresis loss
• B. Magnetic loss
• C. Field loss
• D. Heat loss

13. The magnetic field surrounding a straight conductor is (a) what shape, and (b) is in what position relative to the conductor?

• A. (a) Linked oblong (b) Parallel
• B. (a) Concentric circles (b) Parallel
• C. (a) Linked oblong (b) Perpendicular
• D. (a) Concentric circles (b) Perpendicular

14. Why is a two-pole magnetic field set up around a coil?

• A. Because separate lines of magnetic force link and combine their effects
• B. Because concentric lines of force cross at right angles and combine.
• C. Because lines of force are separated and bent at the coil ends
• D. Because separate lines of force are attracted to the two poles of the coil

15. When a conductor is moving parallel to magnetic lines of force, (a) what relative number of magnetic lines are cut, and (b) what relative value of emf is induced?

• A. (a) Minimum, (b) maximum
• B. (a) Minimum, (b) minimum
• C. (a) Maximum, (b) maximum
• D. (a) Maximum, (b) minimum

16. When the induced voltage in a conductor rotating in a magnetic field is plotted against the degrees of rotation, the plot will take what shape?

• A. A circle
• B. A sine curve
• C. A square wave
• D. A straight line

17. When a loop of wire is rotated through 360º in a magnetic field, the induced voltage will be zero at which of the following points?

• A. 45º
• B. 90º
• C. 180º
• D. 270º

18. When a loop of wire is rotated 360º in a magnetic field, at what points will the induced voltage reach its maximum (a) positive, and (b) negative values?

• A. (a) 0º , (b) 180º
• B. (a) 0º , (b) 270º
• C. (a) 90º , (b) 180º
• D. (a) 90º , (b) 270º

19. When a coil of wire makes eight complete revolutions through a single magnetic field, (a) what total number of alternations of voltage will be generated

and, (b) what total number of cycles of ac will be generated?

• A. (a) 32, (b) 16
• B. (a) 16, (b) 8
• C. (a) 8, (b) 4
• D. (a) 4, (b) 2

20. According to the left-hand rule for generators, when your thumb points in the direction of rotation, your (a) forefinger and (b) your middle finger will indicate the relative directions of what quantities?

• A. (a) Current, (b) Magnetic flux, south to north
• B. (a) Current, (b) Magnetic flux, north to south
• C. (a) Magnetic flux, south to north, (b) Current
• D. (a) Magnetic flux, north to south, (b) Current

21. Continuous rotation of a conductor through magnetic lines of force will produce what type of (a) voltage and (b) waveform?

• A. (a) Ac, (b) sine wave
• B. (a) Dc, (b) continuous level
• C. (a) Ac, (b) sawtooth
• D. (a) Dc, (b) pulsating wave

22. What is the term for the number of complete cycles of ac produced in one second?

• A. Period
• B. Waveform
• C. Frequency
• D. Wavelength

23. What is the unit of measurement for frequency?

• A. Cycle
• B. Hertz
• C. Period
• D. Maxwell

24. A loop of wire rotating at 60 rpm in a magnetic field will produce an ac voltage of what frequency?

• A. 1 Hz
• B. 60 Hz
• C. 120 Hz
• D. 360 Hz

25. An ac voltage of 250 hertz has a period of

• A. 0.004 second
• B. 0.025 second
• C. 0.4 second
• D. 2.5 seconds

26. What is the approximate frequency of an ac voltage that has a period of .0006 second?

• A. 6 Hz
• B. 16.67 Hz
• C. 600 Hz
• D. 1667 Hz

37. An ac voltage has a frequency of 350 Hz. In two seconds, what total number of times will the peak value of voltage be generated?

• A. 350 times
• B. 700 times
• C. 1400 times
• D. 2800 times

38. The value of current of an ac waveform taken at any particular moment of time is what type of value?

• A. Average value
• B. Effective value
• C. Instantaneous value
• D. Peak-to-peak value

39. While the value of an ac voltage may be expressed as one of several values, the accepted practice is to express it as what type value?

• A. Average value
• B. Instantaneous value
• C. Peak-to-peak value
• D. Effective value

40. The total of ten instantaneous values of an alternation divided by ten is equal to what value?

• A. The peak value
• B. The average value
• C. The instantaneous value
• D. The effective value

41. Which of the following mathematical formulas is used to find the average value of voltage for an ac voltage?

• A. E_avg = 0.707 x E_max
• B. E_avg = 1.414 x E_eff
• C. E_avg = 0.636 x E_max
• D. E_avg = 0.226 x E_eff

42. What is the average value of all of the instantaneous voltages occurring during one cycle of an ac waveform with a peak value of 60 volts?

• A. 0 volts
• B. 38 volts
• C. 76 volts
• D. 128 volts

43. If an ac voltage has an E_max of 220 volts, what is E_avg?

• A. 50 volts
• B. 140 volts
• C. 156 volts
• D. 311 volts

44. If an ac waveform has a peak-to-peak value of 28 volts, what is E_avg?

• A. 40 volts
• B. 20 volts
• C. 18 volts
• D. 9 volts

45. If an ac waveform has a peak value of 4.5 amperes, what is its average value?

• A. 2.9 amperes
• B. 3.2 amperes
• C. 5.7 amperes
• D. 6.4 amperes

46. If the average value of current of an ac waveform is 1.2 amperes, what is its maximum value of current?

• A. 0.8 amperes
• B. 0.9 amperes
• C. 1.7 amperes
• D. 1.9 amperes

47. The value of alternating current that will heat a resistor to the same temperature as an equal value of direct current is known as

• A. I_avg
• B. I_eff
• C. Iin
• D. I_max

48. The rms value for an ac voltage is equal to what other ac value?

• A. E_avg
• B. E_max
• C. E_eff
• D. E_in

49. What value will result by squaring all values for E_inst, averaging these values, and then taking the square root of that average?

• A. E_avg
• B. E_max
• C. E_eff
• D. E_in

50. The accepted, nominal value for household power in the United States is 120-volts, 60 Hz. What is the value of maximum voltage?

• A. 170 volts
• B. 120 volts
• C. 85 volts
• D. 76 volts

51. An ac voltmeter is usually calibrated to read which of the following ac values?

• A. Average
• B. Effective
• C. Peak
• D. Peak-to-peak

52. If the maximum value for an ac voltage is known, the E_eff can be found by using which of the following formulas?

• A. E_eff = E_max/0.636
• B. E_eff = E_max/0.707
• C. E_eff = E_max x 0.707
• D. E_eff = E_max x 1.414

53. If the Ieff of an ac waveform is 3.25 amperes, what is I_max?

• A. 4.6 amperes
• B. 2.3 amperes
• C. 2.1 amperes
• D. 1.6 amperes

54. If the rms value of the voltage of an ac waveform is 12.4 volt what is its average value? (Hint: compute E_maxfirst.)

• A. 8 volts
• B. 11 volts
• C. 15 volts
• D. 18 volts

61. Which of the following is an important rule to remember when using Ohm's Law to solve ac circuit problems?

• A. Always solve for resistance first
• B. Give the answer as effective value
• C. Never mix values
• D. Convert all given values to effective before attempting to solve

62. An ac circuit is composed of three 20 - ohm resistors connected in parallel. The average voltage supplied to this circuit is 62-volts ac. What is the maximum current?

• A. 9.3 amperes
• B. 14.6 amperes
• C. 17.5 amperes
• D. 22.5 amperes

63. If the ac source in question 1-62 is raised to an average value of 120 volts, what is the I_eff?

• A. 11.48 amperes
• B. 12.70 amperes
• C. 20.01 amperes
• D. 25.52 amperes

64. If E_eff is 150 volts and I_max is 4.5 amperes, what is the total resistance (R_T) of a circuit?

• A. 21.2
• B. 23.6
• C. 33.3
• D. 47.1

Check your work.

---

This is the Textbook Assignment: Chapter 3, "Direct Current" from the Module 1 — Introduction to Matter, Energy, and Direct Current in Navy Electricity and Electronics Training Series (NEETS) . If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

Figure 3A.—Basic circuit.

IN ANSWERING QUESTIONS 1 THROUGH 3, REFER TO FIGURE 3A.

1. What parts of the circuit represent the (a) source and (b) load?

• A. (a) Es (b) S1
• B. (a) Es (b) R1
• C. (a) S1 (b) R1
• D. (a) S1 (b) Es

2. Which of the following terms describes the circuit condition?

• A. Partially shorted
• B. Partially open
• C. Shorted
• D. Open

3. Which of the following terms describes the figure 3A?

• A. Parts layout
• B. Exploded view
• C. Wiring diagram
• D. Schematic diagram

4. If circuit voltage is held constant, circuit current will react in what manner as the resistance (a) increases, and (b) decreases?

• A. (a) Increase (b) decrease
• B. (a) Increase (b) increase
• C. (a) Decrease (b) decrease
• D. (a) Decrease (b) increase

5. If circuit resistance is held constant, circuit current will react in what manner as the voltage (a) increases, and (b) decreases?

• A. (a) Increase (b) decrease
• B. (a) Increase (b) increase
• C. (a) Decrease (b) decrease
• D. (a) Decrease (b) increase

3-6. According to Ohm’s law, what formula should be used to calculate circuit voltage if resistance and current value are known?

Figure 3B.—Graph of current and voltage.

IN ANSWERING QUESTIONS 7 AND 8, REFER TO FIGURE 3B.

7. If the current is 15 amperes, what is the value of the voltage?

• A. 50 V
• B. 75 V
• C. 100 V
• D. 150 V

8. If the voltage is 200 volts, what is the value of the current?

• A. 10 A
• B. 20 A
• C. 30 A
• D. 40 A

9. Which of the following terms applies to the rate at which an electrical force causes motion?

• A. Power
• B. Energy
• C. Inertia
• D. Each of the above

10. Which of the following circuit quantities can be varied ONLY by varying one of the other circuit quantities?

• A. Voltage
• B. Current
• C. Resistance
• D. Each of the above

11. Which of the following is a correct formula for determining power in an electrical circuit?

• A. P = EI
• B. P = I²R
• C. P = E²/R
• D. Each of the above

12. What is the current in a circuit with 15 ohms of resistance that uses 135 watts of power?

• A. 10 A
• B. 15 A
• C. 3 A
• D. 9 A

13. What is the total power used by a 15-ohm resistor with 4 amps of current?

• A. 60 W
• B. 240 W
• C. 360 W
• D. 900 W

14. What type of resistor should be used in question 3-13?

• A. Carbon
• B. Wirewound
• C. Precision
• D. Composition

15. How much total energy is converted by a 1-horsepower motor in 10 hours?

• A. 7.46 kWh
• B. 8.32 kWh
• C. 8.59 kWh
• D. 9.32 kWh

16. If the energy used by the motor in question 3-15 is 9.5 kWh, what is the efficiency of the motor?

• A. 0.981
• B. 0.904
• C. 0.876
• D. 0.785

Figure 3C.—Series circuit.

IN ANSWERING QUESTIONS 17 THROUGH 23, REFER TO FIGURE 3C.

17. What is the total circuit resistance (R)?

• A. 20 Ω
• B. 60 Ω
• C. 180 Ω
• D. 240 Ω

18. If the circuit current is 3 amps, what is the source voltage (Es)?

• A. 60 V
• B. 180 V
• C. 540 V
• D. 720 V

19. What is the total voltage dropped by each resistor in question 18?

• A. 20 V
• B. 60 V
• C. 180 V
• D. 540 V

20. If the current decreases to 2 amps, what is the total voltage drop across each resistor?

• A. 120 V
• B. 230 V
• C. 310 V
• D. 400 V

21. What would have to be done to the circuit to cause the current to decrease to 2 amps?

• A. The source voltage would have to be increased
• B. The source voltage would have to be decreased
• C. The resistance of R₁ would have to be decreased
• D. One of the resistors would have to be removed from the circuit

22. If the circuit current is 2 amps, what is the total power used by each resistor?

• A. 240 W
• B. 460 W
• C. 620 W
• D. 800 W

23. What is the total power used in the circuit if Es = 360 V?

• A. 720 W
• B. 1380 W
• C. 1860 W
• D. 2400 W

24. When Kirchhoff's voltage law is used to assign polarities to the voltage drop across a resistor, which of the following references is used to indicate the end of the resistor that the current enters?

• A. Ground
• B. Neutral
• C. Negative
• D. Positive

Figure 3D.—Multiple source circuit.

IN ANSWERING QUESTIONS 25 AND 26, REFER TO FIGURE 3D.

25. What is the effective source voltage?

• A. 15 V
• B. 25 V
• C. 50 V
• D. 75 V

26. What is the total amount and direction of current through R₃?

• A. 1.0 A from Y to X
• B. 1.0 A from X to Y
• C. 0.33 A from Y to X
• D. 0.33 A from X to Y

27. Which of the following terms applies to a circuit in which there is NO complete path for current?

• A. Open
• B. Short
• C. Closed
• D. Grounded

28. A circuit in which the resistance is almost zero ohms is referred to by which of the following terms?

• A. Open
• B. Short
• C. Closed
• D. Broken

Figure 3E.—Series circuit and source resistance.

IN ANSWERING QUESTIONS 29 THROUGH 32, REFER TO FIGURE 3E.

29. If R₂ has a short circuit, what will most likely happen to the circuit?

• A. R₁ will be destroyed
• B. Es will increase
• C. V will indicate O volts
• D. S1 will automatically open

30. What is the total voltage drop across Ri when the switch is closed?

• A. 2.5 V
• B. 6.5 V
• C. 97.5 V
• D. 100.0 V

31. What will the meter indicate with (a) S1 open, and (b) S1 closed?

• A. (a) 100 V (b) 100 V
• B. (a) 97.5 V (b) 100 V
• C. (a) 100 V (b) 97.5 V
• D. (a) 97.5 V (b) 97.5 V

32. To achieve maximum power transfer in the circuit, which of the following conditions must be met?

• A. Ri = RL
• B. Is = IL
• C. Es = EL
• D. Ks = KL

33. Maximum power is transferred from a source to a load when the value of the load resistance is of what value when compared to the source resistance?

• A. Equal
• B. Twice
• C. One-half
• D. Several times

34. When maximum power is transferred from a source to a load, what is the efficiency of power transfer?

• A. 5%
• B. 25%
• C. 50%
• D. 95%

35. A circuit consists of three resistors connected in parallel. R1= 30 ohms, R2= 15 ohms, and R3= 10 ohms. If the current through R2= 4 amperes, what is the total source voltage?

• A. 20 V
• B. 60 V
• C. 120 V
• D. 220 V

36. What is the relationship of total current to the current through a component in (a) a series circuit, and (b) a parallel circuit?

• A. (a) Divides (b) divides
• B. (a) Divides (b) equals
• C. (a) Equals (b) equals
• D. (a) Equals (b) divides

37. If a current has a negative polarity when Kirchhoff's current law is applied, which of the following, statements is true of the current?

• A. It is from a battery
• B. It is from a generator
• C. It is entering a junction
• D. It is leaving a junction

38. Three equal resistors are connected in parallel and each resistor has an ohmic value of 300 ohms. What is the equivalent resistance of the circuit?

• A. 100 Ω
• B. 150 Ω
• C. 600 Ω
• D. 900 Ω

39. Three resistors with ohmic values of 120 ohms, 60 ohms, and 40 ohms are connected in parallel. What is the equivalent resistance of the circuit?

• A. 10 Ω
• B. 20 Ω
• C. 30 Ω
• D. 40 Ω

40. Two resistors with ohmic values of 90 ohms and 45 ohms are connected in parallel. What is the equivalent resistance of the circuit?

• A. 10 Ω
• B. 20 Ω
• C. 30 Ω
• D. 40 Ω

41. Which of the following terms describes a single resistor that represents a complex circuit?

• A. Equal resistor
• B. Phantom resistor
• C. Schematic resistor
• D. Equivalent resistor

Figure 3F.—Parallel circuit.

IN ANSWERING QUESTIONS 42 THROUGH 46, REFER TO FIGURE 3F.

42. What is the value of Es?

• A. 336 V
• B. 300 V
• C. 240 V
• D. 120 V

43. What is the value of current through R₂?

• A. 1 A
• B. 2 A
• C. 3 A
• D. 4 A

44. What is the approximate value of total resistance?

• A. 8 Ω
• B. 37 Ω
• C. 112 Ω
• D. 257 Ω

45. What is the value of total power?

• A. 1.2 kW
• B. 1.5 kW
• C. 1.8 kW
• D. 2.0 kW

46. What is the total power consumed by R₃?

• A. 108 W
• B. 240 W
• C. 360 W
• D. 1200 W

Figure 3G.—Series-parallel circuit.

IN ANSWERING QUESTIONS 47 THROUGH 49, REFER TO FIGURE 3G.

47. What is the value of the total resistance?

• A. 3.6 Ω
• B. 15 Ω
• C. 34 Ω
• D. 40 Ω

48. What is the total power used in the circuit?

• A. 22.5 W
• B. 26.5 W
• C. 60.0 W
• D. 250.0 W

49. What is the total voltage drop across R₃?

• A. 8 V
• B. 12 V
• C. 18 V
• D. 30 V

Figure 3H.—Complex circuit.

IN ANSWERING QUESTIONS 50 AND 51, REFER TO FIGURE 3H.

50. What is the value of total resistance?

• A. 5 Ω
• B. 8 Ω
• C. 13 Ω
• D. 15 Ω

51. 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?

• A. 8 V
• B. 26 V
• C. 52 V
• D. 60 V

52. If an open occurs in a series portion of a circuit, what is the effect on (a) total resistance, and (b) total current?

• A. (a) Decreases to zero (b) Becomes infinite
• B. (a) Decreases to zero (b) Decreases to zero
• C. (a) Becomes infinite (b) Becomes infinite
• D. (a) Becomes infinite (b) Decreases to zero

53. If an open occurs in a parallel branch of a circuit, what is the effect on (a) total resistance, and (b) total current?

• A. (a) Increases (b) decreases
• B. (a) Increases (b) increases
• C. (a) Decreases (b) decreases
• D. (a) Decreases (b) increases

54. If a short circuit occurs in a series portion of a circuit, what is the effect on (a) total resistance, and (b) total current?

• A. (a) Increases (b) decreases
• B. (a) Increases (b) increases
• C. (a) Decreases (b) decreases
• D. (a) Decreases (b) increases

55. If a short circuit occurs in a parallel branch of a circuit, what is the effect in (a) total resistance, and (b) total current?

• A. (a) Increases (b) decreases
• B. (a) Increases (b) increases
• C. (a) Decreases (b) decreases
• D. (a) Decreases (b) increases

56. If one branch of a parallel network shorts, what portion of the circuit current, if any, will flow through the remaining branches?

• A. An amount determined by the combined resistance of the remaining branches
• B. All
• C. One-half
• D. None

57. Which of the following circuit quantities need NOT be known before designing a voltage divider?

• A. The current of the source
• B. The voltage of the source
• C. The current requirement of the load
• D. The voltage requirement of the load

THE FOLLOWING INFORMATION IS TO BE USED IN ANSWERING QUESTIONS 58 THROUGH 60: A VOLTAGE DIVIDER IS REQUIRED TO SUPPLY A SINGLE LOAD WITH +150 VOLTS AND 300 MILLIAMPS OF CURRENT. THE SOURCE VOLTAGE IS 250 VOLTS. (HINT: DRAW THE CIRCUIT.)

58. What should be the value of the bleeder current?

• A. 3 A
• B. 300 mA
• C. 30 mA
• D. 3 mA

59. What should be the ohmic value of the bleeder resistor?

• A. 50
• B. 500
• C. 5 kΩ
• D. 50 kΩ

60. What is the value of total current?

• A. 303 mA
• B. 330 mA
• C. 600 mA
• D. 3300 mA

Figure 3I.—Voltage divider.

IN ANSWERING QUESTIONS 61 THROUGH 66, REFER TO FIGURE 3I.

61. Why must the value of R₁ be calculated first?

• A. For convenience
• B. The current through R₂ depends on the value of R₁
• C. The voltage drop across R₁ depends on the value of load 1
• D. In any circuit, values for resistors labeled R1 are calculated first

62. How is the current through R₂ calculated?

• A. By adding IR₁ and the current requirement of load 1
• B. By adding the current requirements of load 1 and load 2
• C. By subtracting the current requirement of load 1 from the current requirement of load 2
• D. By subtracting the current requirement of load 2 from the current requirement of load 1

63. How is the voltage drop across R₂ calculated?

• A. By adding the voltage requirements of load 1 and load 2
• B. By subtracting the voltage drops across R₅ and R₃ from the source voltage
• C. By subtracting the voltage requirement of load 1 from the voltage requirement of load 2
• D. By subtracting the voltage requirements of load 1 and load 2 from the source voltage

64. What is the minimum wattage rating required for R₅?

• A. 1 W
• B. 2 W
• C. 1/2 W
• D. 1/4 W

65. What is the total power supplied by the source?

• A. 3.765 W
• B. 7.965 W
• C. 8.209 W
• D. 8.965 W

66. What is the purpose of using the series-parallel network consisting of R₃, R₄, and R₅ in place of a single resistor?

• A. It provides the desired resistance with resistor values that are easily obtainable
• B. It provides the close tolerance required for the circuit
• C. It is more reliable than the use of a single resistor
• D. It costs less by using three resistors of lower wattage rating than a single, large power resistor

67. A single voltage divider provides both negative and positive voltages from a single source voltage through the use of a

• A. ground between two of the dividing resistors
• B. ground to the positive terminal of the source
• C. ground to the negative terminal of the source
• D. ground to the input of all loads requiring a negative voltage

68. Which of the following voltages are considered dangerous?

• A. Voltages above 115 volts only
• B. Voltages above 230 volts only
• C. Voltages above 450 volts only
• D. All voltages

69. If you discover a possible malfunction in an electric circuit, which of the following actions should be taken?

• A. Attempt repairs yourself
• B. Report the malfunction to a qualified technician
• C. Ignore the malfunction unless you were assigned to repair it
• D. Secure the circuit immediately by removing power at the nearest switch

70. If a person has stopped breathing and there is NO detectable heartbeat, who should perform CPR?

• A. Medical personnel only
• B. The first person on the scene
• C. Emergency Medical Technicians only
• D. Trained, qualified personnel only

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This is the Textbook Assignment: Chapter 2, "Batteries" from the Module 1 — Introduction to Matter, Energy, and Direct Current in Navy Electricity and Electronics Training Series (NEETS) . If you are looking for a reviewer in Electronics Engineering this will definitely help. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Make sure to familiarize each and every questions to increase the chance of passing the ECE Board Exam.

Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. Which of the following is the purpose of an electrical cell?

• A. To change mechanical energy to electrical energy
• B. To change chemical energy to electrical energy
• C. To change electrical energy to mechanical energy
• D. To change electrical energy to chemical energy

2. What are the three basic parts of a cell?

• A. Electrodes, electrolyte, container
• B. Electrodes, acid, water
• C. Anode, cathode, ions
• D. Anode, load, depolarizer

IN ANSWERING QUESTIONS 3 THROUGH 6, SELECT THE PHRASE FROM THE FOLLOWING LIST THAT DESCRIBES THE PART OF A CELL IN THE QUESTION.

I. PARTS OF A CELL

3. Electrolyte

4. Container

5. Anode

6. Cathode

II. DESCRIPTIVE PHRASE

• A. negative electrode
• B. positive electrode
• C. solution acting upon the electrode
• D. mounting for the electrode

7. What term is given to the process that takes place inside a cell?

• A. Electromagnetic action
• B. Piezoelectric action
• C. Electromechanical action
• D. Electrochemical action

8. With respect to recharging a primary or secondary cell, of the following statements, which one is correct?

• A. The secondary cell can be recharged by passing current through it in the proper direction
• B. The primary cell can be recharged by passing current through it in the proper direction
• C. The secondary cell can only be recharged by changing the electrodes
• D. The primary cell can only be recharged by changing the electrolyte

9. What determines the amount of current that a cell can deliver to the external circuit?

• A. The internal resistance of the cell only
• B. The resistance of the external load only
• C. The circuit resistance and the internal resistance of the cell
• D. The circuit capacitance and number of free electrons in the load

10. Which of the following actions will lower the internal resistance of a cell?

• A. Decreasing the size of the electrodes
• B. Increasing the size of the electrodes
• C. Increasing the spacing between the electrodes
• D. Increasing the resistance of the electrolyte

11. What causes negative ions to be attracted to the cathode of a primary cell while the cell is discharging?

• A. A negative charge caused by a loss of electrons
• B. A negative charge caused by an excess of electrons
• C. A positive charge caused by a loss of electrons
• D. A positive charge caused by an excess of electrons

12. What causes hydrogen to be attracted to the anode of a primary cell when the cell is discharging?

• A. A negative charge caused by a loss of electrons
• B. A negative charge caused by an excess of electrons
• C. A positive charge caused by a loss of electrons
• D. A positive charge caused by an excess of electrons

13. What causes the cathode to be "eaten away" in the primary cell while the cell is discharging?

• A. The material of the cathode combines with the negative ions to form a new substance.
• B. The material of the cathode dissolves in the electrolyte.
• C. The material of the cathode leaves the negative terminal of the cell and goes through the load to the anode.
• D. Bacteria in the electrolyte erodes the material in the cathode.

14. The primary cell is completely discharged when which of the following conditions exists?

• A. The cathode is completely eaten away
• B. The active ingredient in the electrolyte is used up
• C. The voltage of the cell is reduced to zero
• D. Each of the above

15. In a zinc-carbon primary cell, what is the function of the carbon electrode?

• A. To generate electrons
• B. To supply a return path for current
• C. To speed electrolysis
• D. To collect hydrogen

16. The lead-acid cell is an example of which of the following types of cells?

• A. The dry cell
• B. The voltaic cell
• C. The primary cell
• D. The secondary cell

17. In a fully charged lead-acid cell, what is the composition of the anode, cathode, and electrolyte respectively?

• A. Zinc, carbon, and water
• B. Carbon, lead, sulfuric acid and water
• C. Lead peroxide, sponge lead, sulfuric acid, and water
• D. Nickel, cadmium, potassium hydroxide, and water

18. Which of the following actions will recharge a secondary cell?

• A. Adding more water to the electrolyte
• B. Adding more active ingredient to the electrolyte
• C. Connecting the negative terminal of a voltage source to the cathode of the cell and the positive terminal of the voltage source to the anode of the cell
• D. Connecting the negative terminal of a voltage source to the anode of the cell and the positive terminal of the voltage source to the cathode of the cell

Figure 2A.—Lead acid chemical actions.

IN ANSWERING QUESTIONS 19 AND 20, REFER TO FIGURE 2A. SELECT THE CORRECT CHEMICAL ACTIONS WITHIN A LEAD-ACID CELL FOR THE CONDITION STATED IN EACH QUESTION.

19. The cell is discharging.

• A. A, C, E, H
• B. A, D, E, G
• C. B, C, F, G
• D. B, D, F, H

20. The cell is charging.

• A. A, C, F, H
• B. B, C, F, H
• C. A, D, F, G
• D. B, D, F, G

21. When all the lead sulfate in a lead-acid cell is converted to sulfuric acid, lead peroxide, and sponge lead, what is the condition of the cell?

• A. Fully charged
• B. Discharged
• C. Sulfated
• D. Unusable

22. Polarization has what effects on an electrical cell?

• A. Decreases internal resistance, thereby increasing the output voltage
• B. Decreases internal resistance, thereby decreasing the output voltage
• C. Increases internal resistance, thereby increasing the output voltage
• D. Increases internal resistance, thereby decreasing the output voltage

23. Which of the following methods is used to control polarization in a cell?

• A. Venting the cell
• B. Heating the electrolyte
• C. Adding mercury to the electrode material
• D. Using an electrolyte that absorbs oxygen

24. Which of the following is caused by local action in a cell?

• A. Shelf life is reduced
• B. Hydrogen is generated in large quantities
• C. Impurities rise to the surface of the electrolyte
• D. Mercury coating of the zinc electrode is worn away

25. In a dry cell, what is the consistency of the electrolyte?

• A. Solid
• B. Liquid
• C. Paste
• D. Powder

26. What serves as the cathode in a common type of dry cell?

• A. Carbon electrode
• B. Zinc container
• C. Steel cover
• D. Nickel terminal

27. How should the dry cell be stored to obtain maximum shelf life?

• A. In a dark container
• B. In a heated cabinet
• C. In a ventilated area
• D. In a refrigerated space

28. The blotting paper in a dry cell serves which of the following purposes?

• A. Separates the paste from the zinc
• B. Permits the electrolyte from the paste to filter through to the zinc slowly
• C. Both A and B above
• D. Keeps the electrolyte dry

29. Of the following characteristics, which one describes the mercury cell?

• A. It is physically one of the largest cells
• B. It has a very stable output voltage
• C. It is designed to be rechargeable
• D. It produces a large amount of current but has a short shelf life

30. Which of the following describes the shorting of a cell?

• A. Decreasing the length of a cell
• B. Connecting the anode and cathode together without a load
• C. Using the cell below its full potential
• D. Providing a recharge voltage that is not sufficient to recharge the cell

31. What is/are the advantages(s) of using a manganese-dioxide-alkaline- zinc cell over the zinc-carbon cell?

• A. Better voltage stability
• B. Longer storage life
• C. Operates over a wide temperature range
• D. All the above

32. What is the common name for manganesedioxide-alkaline-zinc cell?

• A. Alkaline cell
• B. Long-life cell
• C. Moz cell
• D. Manganese-dioxide cell

33. Which of the following factors should be considered when selecting a primary cell as a power source?

• A. Power requirement
• B. Type of electrolyte used
• C. Container material
• D. All of the above

34. Of the following types of cells, which one is a primary cell?

• A. Nickel cadmium
• B. Silver zinc
• C. Lithium organic
• D. Silver cadmium

35. Which of the following is/are the difference(s) in the construction of a NICAD cell as compared to a lead-acid cell?

• A. The electrolyte used
• B. The material of the anode
• C. The material of the cathode
• D. All of the above

36. What is the most common use of a silver-zinc cell?

• A. Flashlight batteries
• B. Automobile batteries
• C. Aircraft storage batteries
• D. Emergency equipment batteries

37. In addition to the nickel-cadmium and silver-zinc cells, which of the following cells uses potassium hydroxide as the active ingredient in the electrolyte?

• A. Lead-acid cell
• B. Silver-cadmium
• C. Lithium-inorganic cell
• D. Magnesium-manganese dioxide cell

38. What is the minimum number of cells necessary to form a battery?

• A. One
• B. Two
• C. Three
• D. Four

Figure 2B.—Battery consisting of five cells.

IN ANSWERING QUESTIONS 39 AND 40, REFER TO FIGURE 2B. EACH CELL IS 1.5 VOLTS AND HAS A CAPACITY OF 1/8 AMPERE.

39. What type of connection is used to combine the cells?

• A. Series
• B. Parallel
• C. Series-parallel

40. What is the (a) voltage output and (b) current capacity of the circuit?

• A. (a) 1.5 volts (b) 1/8 ampere
• B. (a) 1.5 volts (b) 5/8 ampere
• C. (a) 7.5 volts (b) 1/8 ampere
• D. (a) 7.5 volts (b) 5/8 ampere

Figure 2C.—Five cells connected to form a battery.

IN ANSWERING QUESTIONS 41 AND 42, REFER TO FIGURE 2C. EACH CELL IS 1.5 VOLTS AND HAS A CAPACITY OF 1/8 AMPERE.

41. What type of connection is used to combine the cells?

• A. Series
• B. Parallel
• C. Series-parallel

42. What is the (a) voltage output and (b) current capacity of the circuit?

• A. (a) 1.5 volts (b) 1/8 ampere
• B. (a) 1.5 volts (b) 5/8 ampere
• C. (a) 7.5 volts (b) 1/8 ampere
• D. (a) 7.5 volts (b) 5/8 ampere

43. Which of the following diagrams shows the proper connections for obtaining 6 volts at 1/4 ampere? (Each cell is 1.5 volts and has a capacity of 1/8 amp.)

Figure 2D.—Battery consisting of 12 cells.

IN ANSWERING QUESTIONS 44 AND 45, REFER TO FIGURE 2D. EACH CELL EQUALS 1.5 VOLTS AND HAS A CAPACITY OF 1/8 AMPERE.

44. What type of connection is used to combine the cells?

• A. Series
• B. Parallel
• C. Series-parallel

45. What is the (a) voltage output and (b) current capacity of the circuit?

• A. (a) 1.5 volts (b) 1.5 amperes
• B. (a) 4.5 volts (b) 1/2 ampere
• C. (a) 9 volts (b) 1/4 ampere
• D. (a) 18 volts (b) 1/8 ampere

46. What is the first step in performing maintenance on a secondary-cell battery?

• A. Check the level of the electrolyte
• B. Check the technical manual for information on the specific type of battery
• C. Check the terminals for cleanliness and good electrical connection
• D. Check the battery case for cleanliness and evidence of damage

47. When a hydrometer is used to check the specific gravity of the electrolyte in a battery, to what level should the electrolyte be drawn?

• A. Enough to just wet the float
• B. Enough so the float will rise without entering the suction bulb
• C. Enough so the top one-third of the float will rise into the suction bulb
• D. Enough so the float is completely covered by the electrolyte

48. To flush a hydrometer, which of the following liquids should be used?

• A. Sulfuric acid
• B. Salt water
• C. Fresh water
• D. A solution of baking soda and water

49. If the electrolyte level in a battery is low, what should be added to the electrolyte to bring it to the proper level?

• A. Tap water
• B. Sulfuric acid
• C. Potassium hydroxide
• D. Distilled water

50. Which one of the following safety precautions for batteries is NOT correct?

• A. Terminals should be electrically connected together before transporting a battery
• B. Care should be taken to prevent the spilling of electrolyte
• C. Smoking, open flames, and electrical sparks are prohibited around charging batteries
• D. Protective clothing, such as rubber apron, rubber gloves, and face shield, should be worn when working on batteries

51. If electrolyte comes in contact with the skin, what first aid treatment should be given immediately to the affected area?

• A. Cover with petroleum jelly
• B. Wrap with a sterile bandage
• C. Apply an antiseptic lotion
• D. Flush with fresh water

52. A battery with a capacity of 600 ampere-hours should provide 3 amperes for a maximum of how many hours?

• A. 100 hr
• B. 200 hr
• C. 300 hr
• D. 600 hr

53. A battery is rated according to a 20-hour rate of discharge at 300 ampere-hours. Which of the following currents is the maximum current that will allow the battery to deliver its rated capacity?

• A. 15 amperes
• B. 20 amperes
• C. 25 amperes
• D. 30 amperes

54. Which of the following types of routine charges follows the nameplate data in restoring a battery to its charged condition during the ordinary cycle of operation?

• A. Initial
• B. Floating
• C. Normal
• D. Fast

IN ANSWERING QUESTIONS 55 THROUGH 58, MATCH THE DESCRIPTION GIVEN IN THE FOLLOWING LIST WITH THE TYPE OF BATTERY CHARGE IN THE QUESTION.

A. TYPE OF CHARGE

55. Initial charge

56. Equalizing charge

57. Floating charge

58. Fast charge

B. DESCRIPTION

• A. Used in emergency only
• B. Used periodically as part of a maintenance routine
• C. Used to keep a battery at full charge while the battery is idle
• D. Used after electrolyte is added to a dry-shipped battery

59. If violent gassing occurs during the charging of a battery, which of the following actions should be taken?

• A. Increase the room ventilation
• B. Decrease the room temperature
• C. Increase the charging rate
• D. Decrease the charging rate

60. If a battery is being charged at the proper rate, which, if any of the following types of gassing should occur?

• A. Steady gassing
• B. Intermittent gassing
• B. Violent gassing
• C. None

Check your work.

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