Electrical final.doc

1. Which of the following statements is true concerning a poly-phase synchronous propulsion motor?

A. The motor is started as an induction motor.

B. Resistance is gradually added to the rotor circuit.

C. The starting current is held below the rated current.

D. The field winding is energized for starting purposes only.

2. When reading electrical motor controller diagrams, it helps to know that _____

A. current paths in the control circuit are drawn as heavy lines and in the power circuit as lighter lines

B. current paths in the power circuit are drawn as heavy lines and in control circuit as lighter lines

C. circuits subject to 500 volts or greater are drawn as heavy lines and below 500 volts as lighter lines

D. circuits subject to 500volts or greater are drawn as light lines and below 500 volts as heavy

3. Alternating current circuits develop resistance, inductance and capacitance. The inductance of a coil is expressed inA. ohms B. mhos C. henrys D. farads

4. Large cable sizes are formed as individual conductors that may be comprised of several smaller strands to

A. obtain the flexibility required for easy handling

B. reduce the overall weight of the wire run

C. reduce the number of supports needed for a horizontal overhead run

D. all of the above

5. Which of the following is having Di-Electric Constant 80?

A. Air B. water C. Mica D. Caster oil

6. Where a thermal-acting breaker is required to be used in an area of unusually high, low, or constantly fluctuating temperatures, an ambient compensating element must be used. This element consists of a

A. cylindrical spring on the contact arm

B. conical spring on the contact arm

C. second bimetal element

D. second electromagnet

7. Which of the following precautions should you take when securing propulsion generators and motors for an extended period of time?

A. Disconnect the brush pigtails from their contacts and circulate air through the units.

B. Disconnect the brush pigtails from their contacts and discharge carbon dioxide into the units to keep them dry.

C. Lift the brushes from commutator collector rings and use the built-in heater to preventmoisture accumulation.

D. Lift the brushes from commutator collector rings and circulate cool dry air through the units.

8. The direction of magnetic flux changes when the direction of current is reversed.

a. Trueb. False

9. In a Transistor (If Multi choice add option A)

A. PNP and NPN are two basic typesB. Emitter, Collector and Base are the basic Elements.C. Collector separates Base and EmitterD. Emitter separates Base and Collector

10. In a P-Type Semiconductor, the majority current Carriers are holes

11. In a Control Loop System, having Zero (0) Positive Real Values are called …………..Phase current or Error signal

12. If a Motor is not rotating in the E/R, you will carry out the following Checks (multiple choice, 3 Questions of same type but Options were different)

A. Check for the isolation B. Rotate the Coupling with your handC. Check for the Circuit breakerD. Remove the fusesE Look for the Overload TripF. Visually inspect the motor terminalsG. Visually Inspect the Starter TerminalsH. Carry out Infinite Resistance Test

13. Resistance of a wire is increased if the Length is__Increased__ and Area is __decreased___. refer R= specific resistance * length / Area

14. Arrange the following in Increasing Order of their Doping Strength. Answer is-Base, collector, emitterA. Collector, Emitter, BaseB. Base, Emitter, CollectorC. Emitter, Base, CollectorD. Emitter, Collector, Collector Base, Collector, Base

15. Which of the listed precautions should be taken when cleaning the internals of a motor with compressed air?

A. Open the machine on both ends so as to allow the air and dust to escape.

B. Be certain that the circuit breaker is opened and tagged on the feeder panel.

C. Be certain that the air is clean and as dry as possible.

D. Ensure that the fuse in the motor is removed

16. A molded-case breaker provides protection against short-circuits by using a/anA. Shading coil. B. Arc quencher. C. Electromagnet. D. Holding coil.

17. PN diode advantage over vacuum diode?(a)Longer Life,b) No warm up time c) Less delicate d) All of the above

18. IN SQUIRREL CAGE INDUCTION MOTOR SPEED DEPENDS UPON? Speed of the rotating stator field.

19. WHAT IS PIV PEAK INVERSE VOLTAGE

20. WIRES WHY MULTIPLE STANDARDFlexibility

21. Tightly knit metal braid wire can be used with a printed circuit board whenDESOLDERING COMPONENTS IN THE CKT

22. Time delayed or delayed action-type fuses are designed to _____________.

(A) Prevent grounds in branch circuits (B) prevent opens in motor circuits(C) permit momentary overloads without melting(D) guard lighting and electronic circuits

23. Silicon diodes designed for a specific reverse breakdown voltage, become useful as an electronic power supply voltage regulator, called _____________

(A) Tunnel diodes (B) hot-carrier diodes(C) compensating diodes (D) Zener diodes

24. Which of the following statements best describes the material known as varnished cambric?

(A) Felted asbestos sealed with varnish.(B) Cotton cloth coated with insulating varnish.(C) Rubber insulation coated with a layer of tin.(D) Paper impregnated with mineral oil, specially wrapped with nonmetallic tape, and coated with varnish.

25. A synchronous motor maintains synchronism with the rotating field because

(A) Field strength varies directly with rotors lIp(B) DC current applied to the rotor coils causes the rotor magnets to lock in with the rotating flux of the stator(C) the stator poles are dragged around due to the flux created by the excitation current(D) the stator flux rotates in the opposite direction

26. The part of a fuse that melts and opens the circuit is made of

(A) Copper and antimony(B) Steel and Babbitt(C) Aluminum or beryllium alloy(D) Zinc or an alloy of tin and lead

27. The apparent power in inductive circuit

A. True power

B. Lead

C. Inductive

D. Reactive

29. If current reverses, the magnetic field also reverses; true (or) false

a. TRUE

b. FALSE

30. Break down diode____zener diode ___ and___avalanche diode____(reverse biasing)

31. Open loop function system having one zero with positive real value is called __non minimum________ phase function.

32. Semi conductors failed to over current reason low breakdown voltage and _________

33. Which of the listed precautions should take while cleaning poly phase motor internals with compressed air? (Multiple ans)

A. Open the machine as both ends so as to allow the dust to escape

B. Be certain that the circuit breaker is opened, tagged as the feeder panel

C. Be certain that air is clean and as dry as possible

D. Ensure that the fuse is removed

34. Which of the following capacitor is having highest dielectric constant?

A. Air gap

B. Glass

C. Paper

D. Polyester

35. A delayed action fuse is most frequently used in which of the listed circuit?

A. Lighting circuit

B. Motor circuit

C. Electrical heater

D. Padar circuit

36. The current in a semiconductor is produced by

A. Electrons

B. Neutrons

C. Protons

D. Holes

37. If an intrinsic semiconductor is doped with a very small amount of boron then the extrinsic semiconductor set formed, the no. of electrons and holes will

A. Both decreases

B. Increase and decrease

C. Both increases

D. Decrease and increase

38. Series RLC voltage or impedance totals must be calculate by ………………….vectors.

Voltage

39. When the current through the coil of an electromagnet is reversed, the direction of magnetic field also reversed

c. TRUE

d. FALSE

40. A poly phase motor driving an engine room pump fails to start, when trying to identify the cause of failure, which of the following steps are applicable. (Multiple choice)

A. Visually examine the motor for open circuit fault

B. visually examine the starter for open circuit fault

C. Reverse the direction of current for its working

D. Perform the infinite resistance test

41. Which of the following physical character does around rotor induction motor posses that squirrel cage motor does not

A. Slip rings

B. End rings

C. A centrifugal clutch

D. End plates

42. Which of the following conditions will occur when solenoid coil burns out of a cargo winch with a electrical brake.

A. The brake will be set by spring force.

B. The motor will over speed and burns out

C. The load suspended by the cargo boom will fail

D. Nothing will happen; the winch will continue to operate normally

43. A low voltage protection circuit is used in electric motor starting equipment to

A. Trip circuit contractor when the motor over speed due to low voltage

B. Trip circuit contractor when the motor develops short circuit due to low voltage

C. Allows the motor to restart automatically on restoration of voltage without manual resetting

D. Prevent motor from restarting automatically

44. Determine the order of doping in transistor (from high to low)

A. collector, base, emitter

B. Emitter, collector, base

C. Base, emitter, collector

D. collector, emitter, base

45. The opposition to the magnetic lines of force in magnetic is called

A. Resistance

B. Reluctance weber

C. Impedance

D. Inductance

46. Factors varies potential of a PN junction depend on (multiple ans)

A. Type of semiconductor material

B. Amount of doping

C. Temperature

D. None

47. A semiconductor is damaged by a strong current, because of (3 fill in the blanks)

_short circuit__, _overloading___, _overheating___.

48. A poly phase motor driving engine room pumps fails to start, checks

A. Insulation is open

B. No restriction for movement of motor /pump

C. Check overload relay trip

D. Battery fully charged

49. Poly phase motor fails to start, precautions to take before checking

A. Isolate motor

B. Remove fuse

C. Post caution sign

D. Ensure starter/motor terminals are live

50. Which of the following statement is true (*)

A.PNP & NPN are different transistors

B. Emitter, base and collector are basic elements

C. Base separates, emitter, collector

51. Purpose of silicon control rectifier (*Multiple choice)

A. A.C to D.C convertor

B. High voltage stand

52. Generator paralleling

A. Incoming generator freq is less than bus bar frequency

B. Incoming generator frequency is greater than

53. The value of open loop circuit 1.0 added with real value with curve -------------- phase (*qn,fill in the blank)

54. The induced voltage across a stationary conductor in a steady magnetic field is zero. (*)

a. TRUE

b. FALSE

55. Which of the listed devices is used to measure pressure and convert it to an electrical signal?

A. -Transducer

B. -Reducer

C. -Transformer

D. -Rectifier

56. In three phase electrical equipment, the immediate action in the event of fuse blowing in one of the phases would be

a. to replace with a fuse of correct ratingb. to replace fuses on all three phasesc. to try to repair the fused. to investigate the fault that led to blowing the fuse

57.

Which of the capacity has dielectric constant of 1.0000?

Dielectric material is one that reduces the electrostatic force when placed between charges.

a. air gap = 1.006b. vacuumc. waterd. electrolytes

58. Semiconductor forwarding current will be ________ if potential is overcome

59. A poly-phase motor driving an engine room pump fails to start. When trying to identify the cause of failure, which of the following steps are applicable? (Multi choice)

A. Visually examine motor for open circuit faults.

B. Visually examine starter for open circuit faults.

C. Reverse the direction of electrical supply to check if it works.

D. Perform the infinite resistance test.

60. Tightly knit metal braid wire can be used with a printed circuit board when

A. Conductor flexibility is required

B. De-soldering components in the circuit

C. Electrically produced magnetic fluxes would cause inaccuracies in adjacent components

D. Reactance in the circuit must be kept to a minimum

61. Which of the following statements represents an application of a silicon controlled rectifier?

A. To provide DC power for a main propulsion motor.

B. For use as a voltage reference diode.

C. For sensing flame in an automated burner.

D. To eliminate power supply hum.

62. When paralleling an AC generator with live bus bars, which of the following precautions are applicable? (Multi choice)

A. Generator frequency should be slightly lower than bus bar frequency

B. Generator frequency should be slightly higher than bus bar frequency

C. Generator voltage should be in phase with bus bar voltage

D. Generator voltage should be out of phase with bus bar voltage

63. For leading power factor circuits, which of the following can be used?

A. Shunt Capacitors only

B. Shunt Reactors only

C. Either Shunt Capacitors or Shunt Reactors

D. Neither Shunt Capacitors nor Shunt Reactors

64. A fuse that blows often should be replaced only with a fuse of

A. the recommended current and voltage rating

B. higher current and voltage rating

C. higher current and lower voltage rating

D. lower current and higher voltage rating

65. Brushless generators are designed to operate without the use of

A. brushes

B. slip rings

C. commutators

D. all of the above

66. Fuses placed in series with a thermal trip type circuit breaker are used for

A. Time-delay protection

B. Short-circuit protection

C. Short duration surge protection

D. Sustained overload protection

67. In what range of voltages is the transistor in the linear region of its operation?

A. 0 < VCE < 0.7 V

B. 0.7 < VCE < 1.4 V

C. 0.7 < VCE < VCE (max)

D. 0 < VCE < VCE (max)

68. The greatest detrimental effect on idle electrical equipment, such as cargo pump motors, is the

A. Loss of residual magnetism.

B. Absorption of moisture in the insulation.

C. Insulation varnish flaking.

D. Dirt collecting on the windings.

69. Ammeters and voltmeters used in sinusoidal AC power systems indicate which of the following values of the wave forms measured?

A. Peak value

B. Root-mean-square value

C. Average value

D. Maximum value

70. Which of the following statements concerning analog and digital devices are correct?

A. The variables in digital systems are fixed quantities and the variables in analog systems are continuous quantities.

B. There are no basic differences between the two systems.

C. Analog devices are superior in accuracy compared to digital devices.

D. Operations in a digital device are performed simultaneously.

71. While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates that the

A. Motor has started properly.

B. Field windings are grounded.

C. Slip rings are dirty.

D. Power transmission cables are grounded.

72. When the current through the coil of an electromagnet reverses, the direction of the magnetic field also reverses.

a. True

b. False

73. A magnetic blowout coil in a DC motor controller contact or functions to

A. Open contact rapidly.

B. Reduce contact wear.

C. Adjust opening spring tension.

D. Provide "snap-action" in the contactor.

74. In a PNP transistor, the p-regions are

A. Emitter and Base

B. Base and Collector

C. Emitter and Collector

D. Emitter, Base and Collector

75. In an n-type semiconductor, the minority carriers are (1) ___Holes_____

76. In refer compressor what are the readings we are entering in logbook

A. S.W temp

B. S.W Pressure

C. Condenser temp

D. Condenser leak

77. Breakdown diode on zener effect and a valance effect

78. a material having good no. of electron in outer most shell is called a conductor

79. With reference to a Data Logger for a refrigeration system, which of the following parameters should be monitored?

A. Room temperature.

B. Liquid Line temperature.

C. Recharge temperature.

D. Solenoid valve operation.

80. With reference to a Data Logger for a refrigeration system, which of the following parameters should be monitored?

A. Sea water temperature and pressure.

B. Condensing temperature

C. Refrigerant leakage

D. Evaporating temperature

81. AC circuits possess characteristics of resistance, inductance, and capacitance.The capacitive reactance of a circuit is expressed in

A. ohms

B. mhos

C. henrys

D. farads

SECTION 2

DG SHIPPING

1. The shunt used in an ammeter should be connected in____________.(A)series with the load and in parallel with the meter movement(B) parallel with the load and in series with the meter movement(C) parallel with the load and in parallel with the meter movement(D)series with the load and in series with the meter movement

2. Brushless generators are designed to operate without the use of ___________.(A)brushes(B) slip rings(C) commutators(D)all of the above

3. Which of the following physical characteristics does a wound-rotor induction motor possess that asquirrel cage motor does not?

(A) Slip rings(B) End rings(C) A centrifugal switch(D) End plates

4. The current at which a magnetic-type overload relay tends to trip may be decreased by raising the plunger further in to the magnetic circuit of the relay. This action_________.

(A) reduces magneticpull on the plunger and requires more current to trip the relay

(B) reduces magnetic pull on the plunger and requires less current to trip the relay

(C) increases magnetic pull on the plunger and requires more current to trip the relay

(D) increases magnetic pull on the plunger and requires less current to trip the relay

5. Protection against sustained overloads occurring in molded-case circuit breakers is provided bya/an _________.

(A) over voltage release(B) thermal acting trip(C) thermal overload relay(D) current overload relay

6. Which of the listed logic gates is considered to be a BASIC building block (basic logic gate) used in logic diagrams?

(A) NAND(B) OR(C) NOR(D) All of the above.

7. When choosing a battery for a particular application, major consideration should be given to the battery's

(A) amp-hour capacity(B) terminal polarity(C) stability under charge(D) ambient temperature rise

8. The rated temperature rise of an electric motor is the _____________.

(A) average temperature at any given latitude(B) normal temperature rise above the standard ambient temperature at rated load(C) average temperature rise due to resistance at 10% overload(D) permissible difference in the ambient temperature of the motor due to existing

weather conditions9. The electrical energy necessary to transmit a person's voice over a sound-powered telephone circuit is

obtained from ____________.(a) dry cell batteries(b) the ship's service switchboard(c) the emergency switchboard(d) the speaker's voice

10. Local action in a nickel-cadmium battery is offset by _____________.(a) separating the positive and negative plates with plastic spacers(b) separating the positive and negative plates with resin impregnated spacers(c) adding a small amount of lithium hydroxide to the electrolyte(d) trickle charging

11. The freezing point of the electrolyte in a fully charged lead-acid battery will be _____________.(a) higher than in a discharged battery(b) lower than in a discharged battery(c) the same as in a discharged battery(d) higher than in a discharged battery, but the specific gravity will be less

12. What is the maximum allowable primary current of a 2 KVA step-down transformer with a four to one turns ratio if connected across a 440 volt line?

(A)1.1 amps(B) 4.5 amps(C) 18.1 amps(D)27.7 amps

13. Which of the following represents the accepted method of cleaning dust and foreign particles from electrical equipment while limiting damage to electric components?

(A) Carefully wiping off the components with a soft cotton rag.(B) Blowing a high velocity stream of compressed air rapidly across the component(C) Using a vacuum cleaner to remove debris from the components.(D) Using carbon tetrachloride as a cleaning solvent to clean the components.

14. Regarding an AC generator connected to them am electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in armature reaction are compensated for by the _____________.

(A) governor speed droop setting(B) voltage regulator(C) balance coil(D) phase-balance relay

15. In an induction motor, rotor currents are circulated in the rotor by _______

(A) slip rings and brushes(B) an armature and b rushes(C) inductive reaction of the rotating stator field(D) external variable resistors

16. An electrical device which prevents an action from occurring until all other required conditions are met is called a /an ___________.

(A) limit(B) monitor(C) modulator(D) interlock

17. A circuit breaker and a fuse have a basic similarity in that they both _______

(A) can be reset to energize the circuit(B) should open the circuit when overloaded(C) will burn out when an over current flow develops(D) all of the above

18. The electrolyte in a lead-acid storage battery consists of distilled water and _____________.

(A) hydrogen chloride(B) calcium chloride(C) sulfuric acid(D) muriatic acid

19. The full torque electric brake on an electric cargo winch functions to _____________.(A)act as a backup brake in the event the mechanical brake should fail(B) automatically hold the load as soon as current to the machine is shut off(C) automatically govern the lowering speed of the load(D)automatically govern the hoisting speed of the load

20. When troubleshooting most electronic circuits, "loading effect" can be minimized by using a voltmeter with a/an ___________________.

(A) input impedance much greater than the impedance across which the voltage is being measured(B) input impedance much less than the impedance across which the voltage is being measured(C) sensitivity of less than 1000 ohms/volt(D)sensitivity of more than 1000 volts/ohm

21. An electric tachometer receives the engine speed signal from a _______________.(A)small generator mounted on the engine(B) bimetallic sensing device(C) stroboscopic sensing device(D)vibrating reed meter generating a voltage proportionate to engine speed

22. A three-phase alternator is operating at 450 volts with the switchboard ammeter indicating 300 amps. The kw meter currently indicates 163.6 KW, with a power factor of 0.7. If the power factor increases to 0.8, the KW meter reading would increase by ____________.

(A)17.8 KW(B) 23.4 KW(C) 30.6 KW(D)37.8 KW

23. A semiconductor that decreases in resistance with an increase in temperature is known as a ___________.

(A)resistor(B) thermistor(C) diode(D) thermopile

24. The shunt used in an ammeter should be connected in____________.(A)series with the load and in parallel with the meter movement

(B) parallel with the load and in series with the meter movement(C) parallel with the load and in parallel with the meter movement(D)series with the load and in series with the meter movement

25. An operating characteristic appearing on the name plates of shipboard AC motors is _____________.(A) the type of winding(B) input kilowatts(C) temperature rise(D) locked rotor torque

26. Low horsepower, polyphase, induction motors can be started with full voltage by means of ___________.

(A)compensator starters(B) autotransformer starters(C) across-the-line starters(D)primary-resistor starters

27. Moisture damage, as a result of condensation occurring inside of the cargo winch master switches, can be reduced by __________________.

(A) installing a light bulb in the pedestal stand(B) coating the switch box internals with epoxy sealer(C) venting the switch box regularly(D)using strip heaters inside the switch box

28. Where a thermal-acting breaker is required to be used in an area of unusually high, low, or constantly fluctuating temperatures, an ambient compensating element must be used. This element consists of a ______________.

(A)cylindrical spring on the contact arm(B) conical spring on the contact arm(C) second bimetal element(D)second electromagnet

29. Which of the following statements represents an application of a silicon controlled rectifier?(A)To provide DC power for a main propulsion motor.(B) For use as a voltage reference diode.(C) For sensing flame in an automated burner.(D)To eliminate power supply hum.

30. The electrolyte used in a nickel-cadmium battery is distilled water and ______________.(A)diluted sulfuric acid(B) potassium hydroxide(C) lead sulfate(D)zinc oxide

31. Which of the damages listed can occur to the components of a winch master control switch, if the cover gasket becomes deteriorated?

(A)Overheating of the winch motor.(B) Contamination of lube oil.(C) Sparking at the winch motor brushes.(D)Rapid corrosion of switch components.

32. An accidental path of low resistance, allowing passage of abnormal amount of current is known as a/an ____________.

(A)open circuit(B) short circuit(C) polarized ground(D)ground reference point

33. A resistance in a circuit of unknown value is to be tested using the voltmeter/ammeter method. Therefore, the meters should be connected with _____________.

(A)both meters in series with the resistance(B) both meters in parallel with the resistance(C) the ammeter in series and the voltmeter in parallel with the resistance(D) the ammeter in parallel and the voltmeter in series with the resistance

34. SOLAS regulations state that a normal source for emergency loads and power on a cargo vessel must be supplied from ____________.

(A)emergency generator supply to the emergency switchboard(B) emergency generator supply to the main switchboard(C) battery supply to the main switchboard(D)ship's service generator via the emergency switchboard

35. A storage battery for an emergency lighting and power system must have the capacity to _____________.

(A)close all watertight doors twice(B) open all watertight doors four times(C) open and close all watertight doors in six consecutive cycles within a 20 second period(D)none of the above

36. SOLAS regulations require emergency diesel engine starting systems to have sufficient capacity to provide power for at least ____________.

(A) three continuous starting sequences(B) six consecutive cranking cycles(C) nine repeated starts under load(D) twelve cranking periods of 5 seconds

37. Which of the following statements is a Safety regulation concerning emergency generator diesel engines? (SOLAS / Cargo Ship Safety Construction Rules)

(A)The fuel must have a flash point not less than 750F.(B) Emergency diesel engines must be capable of operating under full load in not less than 30

seconds after cranking.(C) The starting battery must produce 12 consecutive cranking cycles.(D)Emergency diesel engines must operate satisfactorily up to a 22.50 list.

38. If an AC motor is started and produces 25 horsepower, the kW meter reading will increase by ___________.

(A)18.65 kW(B) 25.65 kW(C) 30.65 kW(D)37.65 kW

39. While on watch in the engine room at sea with only one ship's service shaft generator on line, the entire plant suddenly blacks out without warning. After restoring power, the cause for this casualty could be attributed to which of the following faults?

(A)The micro switch at the generator speed trip vibrated open, allowing the main breaker to open via the under voltage trip.

(B) Someone pushed the trip button to the "shore power" breaker.(C) The main air compressor suddenly stopped.(D)The standby generator started automatically and became motorized.

40. The function of a rectifier is similar to that of a _______.(a) trap(b) regulating valve(c) check valve(d) Filter

41. The basic control action of a magnetic amplifier depends upon _____________.(a) variations in the load capacitance(b) changes in inductance(c) type of core material(d) construction of the core

Briefly Justify Your Answer

42. The seven segment arrangement for numerical display on consoles, test meters and other applications can be either ________________.

(a) UJT or BJT(b) BCD or OCD(c) JFET or IGFET(d) LED or LCD

43. A silicon controlled rectifier (SCR) is a solid state device used to change ________________.(A) DC to AC and control relatively low load current(B) AC to DC and control relatively high load current(C) DC to AC and control relatively high load current(D) AC to DC and control relatively low load current

44. Which of the following conditions will occur if the solenoid coil burns out on a cargo winch with an electrical brake?

(a) The brake will be set by spring force.(b) The motor will over speed and burn up.(c) The load suspended from the cargo boom will fall.(d) Nothing will happen; the winch will continue to operate as usual.

45. Which of the listed battery charging circuits is used to maintain a wet cell, lead-acid, storage battery in a fully charged state during long periods of disuse?

(a) Normal charging circuit(b) Quick charging circuit(c) Trickle charging circuit(d) High ampere charging circuit

SECTION 3

FINALLY TAKEN FROM NET

1. The full torque electric brake on an electric cargo winch functions to

-act as backup brake in the event the mechanical brake should fail

-automatically hold the load as soon as current to the machine is shut off

-automatically govern the lowering speed of the load

-automatically govern the hoisting speed of the load

2. An electric tachometer receives the engine speed signal from a

-small generator mounted on the engine

-bimetallic sensing device

-stroboscopic sensing device

-vibrating reed meter generating a voltage proportionate to engine speed

3. A semiconductor that decreases resistance with an increase in temperature is known as a

-resistor

-thermistor

-diode

-thermopile

4. The shunt used in an ammeter should be connected in

-series with the load and in parallel with the meter movement

-parallel with the load and in series with the meter movement

-parallel with the load and in parallel with the meter movement

-series with the load and in series with the meter movement

5. Brushless generators are designed to operate without the use of

-brushes

-slip rings

-commutators

-all of the above

6. In the event of a power failure during cargo loading operations, the movement of an electric powered cargo winch will be stopped by

-a manual override switch

-the weight of the load on the boom

-a spring set brake

-a hand operated band brake

7. A ground can be defined as an electrical connection between the wiring of a motor and its

-shunt field

-circuit breaker

-metal framework

-interpole

8. The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the

-prime mover speed

-exciter output voltage

-load on the alternator

-number of poles

9. Which of the following statements represents the main difference between a relay and a contactor?

-Contactors control current, relays control voltage.

-A relay is series connected and contactor is parallel connected.

-Contactors can handle heavier loads than relays.

-Contactors are made from silver and relays are made from copper.

10. The electrolyte used in a nickel-cadmium battery is distilled water and

-diluted sulfuric acid

-potassium hydroxide

-lead sulfate

-zinc oxide

11. Which of the damages listed can occur to the components of a winch master control switch, if the cover gasket becomes deteriorated?

-Overheating of the winch motor.

-Contamination of lube oil.

-Sparking at the winch motor brushes.

-Rapid corrosion of switch components.

12. An accidental path of low resistance, allowing passage of abnormal amount of current is known as a/an

-open circuit

-short circuit

-polarized ground

-ground reference point

13. A resistance in a circuit of unknown value is to be tested using the voltmeter/ammeter method. Therefore, the meters should be connected with

-both meters in series with the resistance

-both meters in parallel with the resistance

-the ammeter in series and the voltmeter in parallel with the resistance

-the ammeter in parallel and the voltmeter in series with the resistance

14. A direct current passing through a wire coiled around a soft iron core is the description of a simple

-magnetic shield

-electromagnet

-piezoelectric device

-electromagnetic domain

15. The use of four diodes, in a full-wave bridge rectifier circuit, will

-provide unidirectional current to the load

-allow a very high leakage current from the load

-convert direct current to alternating current

-offer high opposition to current in two directions

16.A magnetic blowout coil in a DC motor controller contractor functions to

-open contact rapidly

-reduce contact wear

-adjust opening spring tension

-provide "snap-action" in the contractor

17. The method used to produce electron emission in most vacuum tubes is known as

-photoelectric emission

-secondary electric emission

-cold cathodic electric emission

-thermionic emission

18. Which of the listed devices is used to measure pressure and convert it to an electrical signal?

-Transducer

-Reducer

-Transformer

-Rectifier

19. Grounds occurring in electrical machinery as a result of insulation failure are usually caused by

-deterioration due to age

-excessive heat

-vibration

-all of the above

D

20.The amount of voltage induced in the windings of an AC generator depends on

-the number of conductors in series per winding

-the speed at which the magnetic field passes across the winding

-the strength of the magnetic field

-all of the above

21. The device that most commonly utilizes the principle of electromagnetic induction is the

-diode

-transformer

-transistor

-rheostat

22. A tubular fuse should always be removed from a fuse panel with

-a screwdriver

-a pair of insulated metal pliers

-any insulated object

-fuse pullers

23. One factor that determines the frequency of an alternator is the

-number of turns of wire in the armature coil

-number of magnetic poles

-strength of the magnets used

-output voltage

24. Which of the motors for the devices listed below is fitted with an instantaneous overload relay?

-Fan

-Pump

-Winch

-Machine tool

25. Which of the following statements concerning an analog device and a digital device is correct?

-The variables in digital systems are fixed quantities, and the variables in analog systems are continuous quantities.

-There are no basic differences between the two systems.

-Analog devices are superior in accuracy compared to digital devices.

-Operations in a digital device are performed simultaneously.

26. The number of cells in a 12 volt lead-acid battery is

-three cells

-four cells

-six cells

-twelve cells

27. When choosing a battery for a particular application, major consideration should be given to the battery's

-amp-hour capacity

-terminal polarity

-stability under charge

-ambient temperature rise

28. Electrical leads and insulation on a motor should be painted with

-heat-resisting acrylic

-heat-resisting aluminum

-insulating varnish

-insulating white lead

29. Voltage generator by most AC generators is fed from the machine to the bus by means of

-brushes on a commutator

-brushes on slip rings

-slip rings on a commutator

-direct connections from the stator

30. A circuit breaker differs from a fuse in that a circuit breaker

-melts and must be replaced

-is enclosed in a tube of insulating material with metal ferrules at each end

-gives no visual indication of having opened the circuit

-trips to break the circuit and may be reset

31. Incandescent lamps are classified according to

-shape of bulb and type of service

-size and style of base

-operating voltage and wattage

-all of the above

32. As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to

-draw a one line diagram of the circuitry

-test all fuses and measure the line voltage

-take megger readings

-insulate the apparatus from ground

33. An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a

-magnetic amplifier

-ship's service alternator

-three-wire DC generator

-saturable core reactor

34. The state of charge of a lead acid storage battery is best indicated by the

-testing of the individual cell voltages

-ampere hour capacity of the battery

-specific gravity of the electrolyte

-total cell voltages

35. The first requirement for logical troubleshooting of any system is the ability to

-collect all available data on a casualty

-recognise normal operation

-identify the probable cause of a symptom

-isolate the faulty component

36. The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor

-load limit settings

-idle speed settings

-speed limit settings

-speed droop settings

37. The open circuit voltage of a fully charged lead-acid battary cell is

-1.5 v

-1.8 v

-2.0 v

-2.3 v

38. In an AC generator, direct current from a separate source is passed through the windings of the rotor

-by means of slip rings and brushes

-by means of a commutator

-by means of rotating bar magnet

-to minimize the danger of arc over

39. A delayed-action fuse is most frequently used in which of the listed

circuits?

-lighting circuit

-motor circuit

-electric heater circuit

-radar circuit

40.Which of the listed procedures should be carried out to prevent moisture damage to electrical apparatus during extended periods of idleness?

-fill the motor housing with CO2 to inert the space

-strap silica gel around the commutator

-place heat lamps in the motor housing

-cover the equipment with a canvas tarpaulin

41. A fuse of recommended current and voltage ratings that blows often should be replaced only with a fuse of

-the same ratings

-higher ratings

-higher current and lower voltage rating

-lower current and higher voltage rating

42. Which of the listed conditions is an advatage of a PN diode over a vacuum diode?

-longer life

-no warm up time

-less delicate

-all of the above

43. The freezing point of the electrolyte in a fully charged lead-acid battery will be

-higher than in a discharged battery

-lower than in a discharged battery

-the same as in a discharged battery

-higher than in a discharged battery, but the specific gravity will be less

44. To repair a small electrical motor that has been submerged in saltwater, you should

-wash it with fresh water and apply an external source of heat

-renew the windings

-send it ashore to an approved service facility

-rinse all electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the motor with compressed air

45. The basic measuring unit of inductance is the

-coulomb

-ohm

-farad

-henry

46. Which of the listed precautions should be taken when cleaning the internals of a motor with compressed air?

-open the machine on both ends so as to allow the air and dust to escape

-be certain that the circuit breaker is opened and tagged on the feeder panel

-be cetain that the air is clean and as dry as possible

-all of the above

47. The pupose of DC generator brushes is to

-neutralize armature reaction

-conduct electric current to an outside circuit

-convert DC current to AC current

-provide excitation to a DC generator

48. Fuses are rated in

-voltage

-amperage

-interrupting capacity

-all of the above

49. Power transformers are rated in

-kilowatts

-ampere-turns

-kilowatt-volts

-kilovolt-amperes

50. Alternative current circuits develop resistance, inductance and capacitance. The inductance of a coil is expressed in

-ohms

-mhos

-henrys

-farads

51. A lead-acid battery is considered fully charged when the

-electrolyte gasses freely

-battery charger ammeter indicates a positive reading

-terminal voltage reaches a constant value at a given temperature

-specific gravity of all cells reaches the correct value and no longer increases over a period of 1 to 4 hrs

52. The insulation resistance of electric equipment and machinery should be tested for the lowest normal insulation values

-immediately after shutting down the machine

-every time the brush rigging is adjusted

-immediately after starting up the machine

-every 30 days whether the machine is in use or not

53. High vacuum diodes, gas-filled diodes, and germanium semiconductor diodes may all be used as

-potentiometers

-rectifiers

-power sourses

-photocells

54. The apparent power in a purely inductive circuit is also known as

-true power

-lead power

-induced power

-reactive power

55. Which of the following devices will prevent a DC generator from becoming motorized?

-overcurrent relay

-motorization trip

-reverse power relay

-reverse current relay

56.A grounded switch or cable will be indicated by a meg ohmmeter reading of

-infinity

-zero

-being unsteady in the high range

-being unsteady in the low range

57. Regarding battery charging rooms, ventilation should be provided

-at the lowest point of the room

-horizontally near the batteries

-at the highest point of the room

-only when charging is in progress

58. The main difference between an electron tube and a transistor is the

-type of function they can perform

-reaction of electron flow through a gas or vacuum in a transistor

-reaction of electron flow through a semiconductor when placed in a tube

-reaction of electron flow through a semiconductor used to form a transistor

59. A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to

-check for shorted coils with a growler

-take moisture readings with a hydrometer

-test insulation values with a megger

-ground the commutator, or slip rings and run it at half load for 12 hours

60. Before testing insulation with a meg ohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to test, because the

-static charge of the machine may give a false reading

-armature will have a greater number of leakage paths

-insulation may be damaged

-insulation may be covered with moisture

61. In a DC series circuit, all the conductors have the same

-power expended in them

-voltage drop across them

-resistance to current flow

-current passing through them

62. A three-phase induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged?

-overspeed trip

-thermal overload relay

-three-pole safety switch

-magnetic blowout coil

63. Most three-phase induction motors used for driving engine room auxiliaries are started by

-resistor starters

-across-the-line starters

-impedance starters

-reactor starters

64. When electrical cables penetrate watertight bulkheads,

-they should be grounded on either side of the bulkhead

-they must be bent to a radius of six diameters

-a watertight stuffing tube capable of accepting packing should be employed

-they should be secured by a clamp

65. Across-the-line starters are used with AC motors to provide

-reduced starting current

-regulated starting current

-high starting torque

-controled starting acceleration

66. Most conductive materials such as copper, aluminium, iron, nickel

-increase in resistance with increased temperature

-increase in resistance with decreased temperature

-decrease in resistance with increased temperature

-decrease in resistance with decreased temperature

67. The electrician reports to you that he has obtained low (but above 1 megohm) megger readings on the windings of a deck winch motor. Upon checking the records of that motor, you find the readings have consistently been at the same level the last six years. You should, therefore, recommend that the

-motor be replaced

-windings be dried

-windings be cleaned

-readings are acceptable

68. Line losses in a distribution circuit are kept to a minimum by

-adding rubber insulation conductors to the circuit

-using higher current and lower voltage

-increasing the number of thermal relays in the circuit

-using higher voltage and lower current

69. Adding resistance in series with the field winding of a DC shunt motor without a load, will cause the motor speed to

-increase

-decrease

-remain the same

-fluctuate rapidly

70. The function of the compensating windings used in a DC generator is to

-prevent cross-commutation

-increase armature coil strength

-increase field strength

-neutralize armature reaction

71.Capacitors are used on the output of the power supply in today's consoles to

-filter out "ripple"

-prevent overloads

-act as a permanent load

-decrease the average value of the output voltage

72. The purpose of a motor under voltage protection device is to

-prevent high armature current when power is restored

-start the motor at a very low voltage

-trip the load off the motor in case of fire

-protect personnel from low voltage shocks

73. In testing a three-phase delta winding for an open circuit using a meg ohmmeter, you must

-test each phase with all connections intact

-measure the voltage across the open connections while testing

-test the windings as parallel groups to avoid short circuiting

-open the delta-connections to avoid shunting the phase being tested

74. The direction of rotation of an induction motor is

-opposite to the rotating field

-the same as the direction of the rotating field

-determined by the number of poles

-determined by the staggering of the brushes

75. mercury filled thermometers should never be used to determine the temperature of the battery electrolyte because accidental breakage of

the thermometer can cause

-severe sparking and explosions

-rapid oxidation of battery plates

-contamination of the electrolyte

-corrosion on the battery terminals

76. The purpose of a main switchboard circuit breaker's revers-power trip is to

-prevent main circuit overload

-protect the circuit breaker blowout coil

-prevent alternator motorization

-prevent low voltage tripout

77. When charging lead-acid batteries, the charging rate should be reduced as the battery nears its full charge to

-prevent damaging battery plates

-allow equalization of cell voltages

-reduce lead sulfate deposites

-increase lead peroxide formation

78. Regarding an induction motor, the power developed by the rotor automatically adjusts itself to

-power required to drive the load

-speed required to drive the load

-current flow in the motor stator

-torque developed by the rotating field

79. The purpose of a magnetic relay is to

-open a circuit only in the event of overload

-remotely open and close contacts

-provide overcurrent protection during starting

-relay voltages at increased power

80. A semiconductor is a material with a

-conductivity higher then a normal conductor

-conductivity higher then a normal insulator

-high conductivity at low temperatures

-low conductivity at high temperatures

SECTION 4

1. For a given line voltage, four heating coils will produce maximum heat when connected in-Parallel

2. The unit of absolute permittivity of a medium is-Farad/ metre

3. The unit of electric intensity is-Volt/ metre

4. In practice , earth is chosen as a place of zero electric potential because it-Has almost constant potential

5. Current carried by each of the two long parallel conductors is doubled. If their separation is also doubled , force between them is-Increase two fold

6. The direction of induced EMF can be found with the help of -Lenz’s Law

7. Permanent magnets are generally made of-Alnico alloys

8. The rate of rise of current through an inductive coil is maximum-At the start of the current flow

9. A material with very less flow of electrons is called insulator

10. VGS and Id approximately zero....this is called ____cut off _________ voltage

11. The winding resistance of a coil can be increased by _______ the number of turns or using a ______ wire.

A. increasing, thicker

B. decreasing, thicker

C. increasing, thinner

D. decreasing, thinner

12. The most common source of excitation for synchronous motors is a/an _____________.(A) low voltage battery(B) motor attenuator set

(C) DC exciter generator(D) AC supply

13. A sine wave consists of no of cycles 2 cycles

14. On an engine throttle control system, the aux control circuits are provided with devices to prevent excessive over travel of the pilot valve by the synchronous motor these devices are called.

A. overlap sensor

B. limit switch

C. over travel relay

D. proximity switch

15. The speed of the squirrel cage induction motor is determined by

A. Dia of stator

B. No of stator poles

C. Rotor winding resistance

D. Bar resistance of conducting rotor

16. The method used to produce electron emission in most vacuum tubes is known as

A. Photo electric emission

B. Secondary electric emission

C. Cold cathodic electric emission

D. Thermionic emission

17. A reverse current relay prevents dc generator motorization automatically by option

A. Redirecting up prime mover,

B. Securing the exciter generator,

C. Tripping the circuit breaker.

18. The output voltage of a there phase alternator is regulated by

dc voltage to the field.

19. Di electric constant of 3.6

A. Water

B. Paper

C. Electrolyte

D. Air

20. RMS value of a sine wave current is expressed as

A. Average value,

B. Max value

C. Effective value

D. Instantaneous value

21. Which of the following statements comparing transistors and vacuum tubes is correct?

A. Both transistors and vacuum tubes have a cathode that must be heated to give off electrons.

B. A vacuum tube must have a heated cathode, where transistors do not.

C. Neither transistors nor vacuum tubes require heat for electrons to flow.

D. The anode of both transistors and vacuum tubes must be heated to give off electrons.

NEW SECTION - 1

1. Electric and electro-hydraulic steering gear motors are required by Coast Guard Regulations (46 CFR) to be _________.

A. protected by a circuit breaker set at 125% and a thermal overload device

B. provided with a running motor overcurrent protection device

C. served by a single two conductor cable

D. served by two feeder circuits