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 prevent
moisture 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 types
B. Emitter, Collector and Base are the basic Elements.
C. Collector separates Base and Emitter
D. Emitter separates Base and Collector
10. In a P-Type Semiconductor, the majority current Carriers are
holes11. 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 hand
C. Check for the Circuit breaker
D. Remove the fuses
E Look for the Overload Trip
F. Visually inspect the motor terminals
G. Visually Inspect the Starter Terminals
H. 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 / Area14. Arrange the following in Increasing
Order of their Doping Strength. Answer is-Base, collector,
emitterA. Collector, Emitter, Base
B. Base, Emitter, Collector
C. Emitter, Base, Collector
D. 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 removed16. A molded-case
breaker provides protection against short-circuits by using
a/an
A. 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 circuits23. 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 diodes24. 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 direction26. 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 __________ 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 removed34. Which of the following
capacitor is having highest dielectric constant?
A. Air gapB. GlassC. PaperD. Polyester35. A delayed action fuse
is most frequently used in which of the listed circuit?A. Lighting
circuitB. Motor circuitC. Electrical heaterD. Padar circuit36. The
current in a semiconductor is produced by
A. ElectronsB. NeutronsC. ProtonsD. Holes37. 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 decreaseC. Both increasesD.
Decrease and increase38. Series RLC voltage or impedance totals
must be calculate by .vectors.
Voltage39. When the current through the coil of an electromagnet
is reversed, the direction of magnetic field also reversedc. TRUEd.
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 faultB. visually
examine the starter for open circuit faultC. Reverse the direction
of current for its workingD. Perform the infinite resistance
test41. Which of the following physical character does around rotor
induction motor posses that squirrel cage motor does not
A. Slip ringsB. End ringsC. A centrifugal clutchD. End plates42.
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 outC. The load suspended by the cargo boom will
failD. Nothing will happen; the winch will continue to operate
normally43. 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
voltageB. Trip circuit contractor when the motor develops short
circuit due to low voltageC. Allows the motor to restart
automatically on restoration of voltage without manual resettingD.
Prevent motor from restarting automatically
44. Determine the order of doping in transistor (from high to
low)
A. collector, base, emitterB. Emitter, collector, baseC. Base,
emitter, collectorD. collector, emitter, base45. The opposition to
the magnetic lines of force in magnetic is called
A. ResistanceB. ReluctanceC. ImpedanceD. Inductance
46. Factors varies potential of a PN junction depend on
(multiple ans)
A. Type of semiconductor materialB. Amount of dopingC.
TemperatureD. 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,
checksA. Insulation is openB. No restriction for movement of motor
/pumpC. Check overload relay tripD. Battery fully charged 49. Poly
phase motor fails to start, precautions to take before checking
A. Isolate motorB. Remove fuseC. Post caution signD. Ensure
starter/motor terminals are live50. Which of the following
statement is true (*)
A.PNP & NPN are different transistors B. Emitter, base and
collector are basic elementsC. Base separates, emitter,
collector51. Purpose of silicon control rectifier (*Multiple
choice)
A. A.C to D.C convertorB. High voltage stand52. Generator
paralleling
A. Incoming generator freq is less than bus bar frequencyB.
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. -Rectifier56. 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 fuse57. Top of Form
Which of the capacity has dielectric constant of 1.0000?a. air
gapb. vacuumc. waterd. electrolytes
58. Semiconductor forwarding current will be ________ if
potential is overcome59. 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)
___electrons____
76. In refer compressor what are the readings we are entering in
logbookA. 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 characteristicsdoes 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 con sidered 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
ambienttemperature of the motor due to existing weather
conditions
9. 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 voice10.
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 charging11. 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 less12. 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 amps13. 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 tothem 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 brushes
(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) interlock17. 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
[email protected](a) trap
(b) regulating valve(c) check valve(d) Filter41. 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
coreBriefly 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 LCD43. 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 circuitSECTION 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 coil62. 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 41. For a given line voltage, four heating coils will
produce maximum heat when connected in-
2. 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
-Lenzs 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 flow9. 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 supply13. 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 emission17. 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. Air20. RMS value of a sine wave current is expressed as A.
Average value,
B. Max value
C. Effective value
D. Instantaneous value21. 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 circuitsTo prevent the race of a dc
series motor what arrangement should make?A.allways start at heavy
load.B.use a strong series-weak shunt compound dc motor.C.use a
weak series- strong shunt compound dc motor.D. All of the
above.