Electricity

(1.1.10.1.2-2) How would a circuit with a blown fuse be described? (a) an open circuit (b) a bonded circuit (c) a grounded circuit (d) a short circuit

a

(1.1.10.1.2-3) For what purpose are time delayed or delayed action-type fuses used? (a) permit momentary overloads without melting (b) prevent opens in motor circuits (c) guard lighting and electronic circuits (d) prevent grounds in branch circuits

a

(1.1.10.1.2-6) In a single element cartridge-type fuse, what type of protection is provided for lighting and general power applications? (a) short-circuit protection using a fusible link (b) sustained overload protection using a spring loaded soldered joint (c) sustained overload protection using a fusible link (d) short-circuit protection using a spring loaded soldered joint

a

(1.1.10.3.1-4) Why must accidental grounds in a shipboard electrical system be repaired as soon as possible? (a) they may damage insulation and may cause power outages (b) they will overload the ground detection system (c) they will result in immediate power outages (d) they may damage circuit breakers

a

(1.1.11.3.2-1) Which of the following conditions would most likely lead to the failure of a resistor due to overheating? (a) Resistor wattage rating one-half that required for the circuit. (b) Resistor wattage rating two times higher than that required for the circuit. (c) Resistor wattage rating four times higher than that required for the circuit. (d) Resistor wattage rating equal to that required for the circuit.

a

(1.1.13.1.1-11) What operational characteristic is associated with the illustrated manual starter circuit for a motor shown in figure "A"? Illustration EL-0023 (a) has no low voltage protection and the motor may be damaged if the voltage drops below a certain level (b) incorporates low voltage release because the motor will stop when voltage falls below a certain value and automatically start when normal voltage resumes (c) incorporates low voltage protection because the motor will stop when voltage falls below a certain value but must be manually restarted when normal voltage resumes (d) incorporates low voltage protection because the motor will stop when voltage falls below a certain value and automatically start when normal voltage resumes

a

(1.1.13.1.1-13) What is the name of the type of motor control circuit that will not permit automatic restarting after power is restored, following a power failure? (a) low voltage protection (b) low voltage release (c) overload lockout (d) reduced voltage restart

a

(1.1.13.1.1-2) Which of the following illustrated manual motor starters represents the wiring diagram illustrated in figure "A"? Illustration EL-0023 (a) 1 (b) 2 (c) 3 (d) 4

a

(1.1.13.1.1-4) What is the functional name of an electrical device which prevents simultaneous energization of loads thereby preventing damage or injury? a) electrical interlock device (b) monitoring device (c) modulating device (d) mechanical limit device

a

(1.1.14-1) At a minimum threshold, how many milliamps of current through the body produces a painful sensation that most people would perceive as an electric shock? • (a) 3 to 7 mA o (b) 10 to 16 mA o (c) 30 mA o (d) 100 mA for 2.5 sec.

a

(1.1.14-7) Which of the following devices would be forbidden to use as a primary means of electrical isolation? (a) start/stop push button station (b) non-fused disconnect switch (c) circuit breaker (d) fused disconnect switch

a

(1.1.2.1-12) What is the name of the force that causes free electrons to flow in a conductor producing electric current? (a) electromotive force (b) dielectric force (c) inductive force (d) resistant force

a

(1.1.2.1-13) What is the correct name for current that flows in only one direction? (a) direct current (b) alternating current (c) sinusoidal current (d) omnidirectional current

a

(1.1.2.1-18) How does the resistance of a conductor vary? (a) directly as its length and inversely as its cross-sectional area (b) inversely as its length and directly as its cross-sectional area (c) inversely as its length and inversely as its cross-sectional area (d) directly as its length and directly as its cross-sectional area

a

(1.1.2.3-10) Which of the electrical properties listed will always be the same across each component in a parallel circuit? (a) Voltage (b) Resistance (c) Impedance (d) Current

a

(1.1.2.3-7) Which of the following statements is true concerning circuits with parallel connected resistances? (a) The total current flow equals the sum of the individual currents. (b) The total resistance equals the sum of the individual resistance. (c) The total current flow equals the reciprocal of the sum of the individual currents. (d) The total voltage equals the sum of the individual voltages across each resistance.

a

(1.1.3.1.1-1) Why are space heaters provided on larger generators? (a) maintain rotor and stator winding temperatures above the dew point to prevent the formation of condensation (b) prevent condensation in the lube oil (c) prevent electrolysis due to condensation in the bearings (d) keep the machine at ambient temperature of the machinery space

a

(1.1.3.1.3-4) How is the power factor of an AC generator operating singularly determined? (a) the connected load (b) the prime mover speed (c) the generator's rated voltage (d) the ground current

a

(1.1.3.1.3-8) How are the number of cycles per second developed by the alternator aboard your vessel determined? (a) the speed of the engine driving the alternator (b) the resistance applied to the field rheostat (c) the adjustments made to the voltage regulator (d) the synchronous speed of induction

a

(1.1.3.1.3-9) How is the frequency of an alternator at a given RPM determined? (a) by the number of magnetic poles (b) by the number of turns of wire in the armature coil (c) by the strength of the magnets used (d) by the output voltage

a

(1.1.6.1.1-1) What should be the primary consideration when choosing a battery for a particular application? (a) amp-hour capacity (b) stability under charge (c) terminal polarity (d) ambient temperature rise

a

(1.1.6.1.1-3) The individual 6 volt lead-acid batteries, when connected as shown in the illustration, as a battery bank would produce how many volts? Illustration EL-0070 (a) 6 (b) 12 (c) 18 (d) 24

a

(1.1.6.1.3-2) In general, why are nickel-cadmium storage batteries superior to lead-acid batteries? (a) they can remain idle and keep a full charge for a long time (b) they need fewer cells in series and use less mounting space (c) they are less costly to replace (d) they put out higher voltages and require no maintenance

a

(1.1.6.2.1-5) When a battery is continuously exposed to low temperatures, what is the best procedure to keep it from freezing? (a) keep the battery fully charged (b) disconnect the battery (c) remove the battery caps (d) securely cover the battery

a

(1.1.6.2.1-7) Under normal conditions, storage batteries used for starting the emergency dieselgenerator are maintained in a charged state by which of the following methods? (a) Trickle charging (b) Reverse charging (c) Fast charging (d) Equalizing charge

a

(1.1.6.3.2-2) When troubleshooting a lead-acid storage battery, what is the best method for detecting a weak or dead cell? (a) comparing the specific gravity of the electrolyte in each cell (b) taking each cell's temperature with a calibrated mercury thermometer (c) visually inspecting the electrolyte levels of each cell (d) taking an open circuit voltage test of individual cells

a

(1.1.10.3.1-2) Multiple grounds have developed and were initially indicated by the ground-detecting system as one ground. What is the FIRST step in locating the grounds? (a) change over generators (b) eliminate the individual circuits one by one until the ground detecting system no longer indicates any grounds (c) check each circuit with a megohmmeter (d) examine the main bus bars for signs of overheating

b

(1.1.11.3.2-2) What would be the indication of a burned-out LED? (a) excessive output (b) no illumination (c) excessive illumination (d) a slight glow in the crystal

b

(1.1.13.1.1-5) Why are motor controllers seldom troubled with grounds? (a) there are separate switches for the motor and the control (b) the contactors and relays are mounted on a non-conducting panel (c) the auxiliary contacts have a high resistance connection (d) the resistor banks are composed of individual series-connected units

b

(1.1.13.1.1-7) Which of the following statements represents the main difference between a relay and a contactor? (a) Contactors are made from silver and relays are made from copper. (b) Contactors contacts can handle heavier loads than relay contacts. (c) Contactors control current and relays control voltage. (d) A relay is series connected and a contactor is parallel connected.

b

(1.1.14-10) After prior isolation and lock-out/tag-out procedures are performed, which electrical device requires discharging any stored electrical energy before any work may safely begin? (a) resistor bank (b) capacitor (c) potential transformer (d) choke coil

b

(1.1.14-2) At a minimum threshold, how many milliamps of current through the body produces a condition where most people would be unable to let go of the energized electrical conductor due to involuntary muscular contraction? (a) 3 to 7 mA (b) 10 to 16 mA (c) 30 mA (d) 75 mA for 5 sec.

b

(1.1.14-5) With all other factors considered equal (such as voltage, conducting path through the body and the duration of contact), contact with an energized electrical system conductor of which system type would produce the most damaging effect? (a) DC systems (b) 60 Hz AC systems (c) 10 kHz AC systems (d) All the above systems would be equally as damaging

b

(1.1.14-6) Before electrical work can be safely undertaken, the equipment must be de-energized, locked and tagged out, and verification must be made that the circuit is actually dead. What testing device is most certain to reliably verify that a circuit is actually dead? (a) a non-contact voltage tester (b) an autoranging digital multimeter (c) a solenoid type voltage tester (d) a non-autoranging digital multimeter

b

(1.1.14-8) Which of the following voltage testers would be associated with high quality, be safe to use, and minimize the electric shock hazard? (a) a voltage tester with a low input impedance and a lower voltage rating than any expected measured voltages (b) a voltage tester with a high input impedance and a voltage rating higher than any expected measured voltages (c) a voltage tester with a low input impedance and a higher voltage rating than any expected measured voltages (d) a voltage tester with a high input impedance and a lower voltage rating than any expected measured voltages

b

(1.1.2.1-16) The resistance of most conducting materials will change as a result of temperature change. What will happen to the resistance of copper wire when the temperature increases? (a) remains constant (b) increases in a predictable way (c) changes in an unpredictable way (d) decreases in a predictable way

b

(1.1.2.1-17) What will happen to an electrical coil when the direct current flowing through the coil is increasing? (a) the increasing current reduces the power consumed (b) the increasing current produces a voltage in opposition to the applied voltage (c) the increasing current changes the coil's impedance (d) the increasing current reduces the amount of flux produced

b

(1.1.2.1-4) What property does capacitance have in an AC circuit? (a) rectify the current (b) oppose any change in circuit voltage (c) stop current flow once the capacitor is fully charged (d) allow current flow in only one direction

b

(1.1.2.3-4) What will happen to the total circuit resistance when additional parallel circuits are added to a circuit? (a) it will increase, causing a decrease in the line voltage (b) it will decrease, causing an increase in the total load current (c) it will decrease, causing an increase in the line voltage (d) it will increase, causing a drop in the total load current

b

(1.1.3.1.3-10) What is the most practical way to control the voltage output of an AC generator? (a) varying the speed of the rotating field (b) varying the strength of the rotating magnetic field (c) varying the number of windings (d) varying the power factor of the load

b

(1.1.3.2-2) Rotor-to-stator air gap readings should be periodically taken for electrical generation equipment. What is the best tool to use to take these measurements? (a) cloth (non-metallic) tape measure (b) tapered, long blade, feeler gage (c) dial indicator (d) inside micrometer

b

(1.1.4.3.3-2) The winch shown in the illustration will operate normally in all speeds in both directions, with the exception that it will not accelerate into 'fifth point' hoist or 'fifth point' lower. What would be a possible cause? Illustration EL-0102 (a) master switch contacts 'MS 8' are welded closed (b) time delay relay '3T' coil is open-circuited (c) master switch contact 'MS 7' fails to close (d) the contactor '5A' coil is open-circuited

b

(1.1.5.1-2) If the voltage supplied to the lighting circuit is 110 volts, how much current is drawn by a 100 watt light bulb? (a) 0.08 amps (b) 0.91 amps (c) 1.10 amps (d) 90.9 amps

b

(1.1.5.1-4) What will be the resulting current when a voltage of 115 VDC is applied to a resistance of 12 ohms in figure "A" of the illustrated circuit with the switch closed? Illustration EL-0018 (a) 1.24 amps (b) 9.58 amps (c) 104.34 amps (d) 127 amps

b

(1.1.5.1-6) What will be the resulting current when a voltage of 110 VDC is applied to a resistance of 32 ohms in figure "A" of the illustrated circuit when the switch is closed? Illustration EL-0018 (a) 0.29 amps (b) 3.44 amps (c) 9.31 amps (d) 142 amps

b

(1.1.5.1-8) What would be the total current flowing in the circuit shown in figure "B" of the illustration if the source is 30 volts, the resistance of R1 is 10 ohms, R2 is 10 ohms and R3 is 10 ohms, respectively? Illustration EL-0032 (a) 1 amp (b) 2 amps (c) 5 amps (d) 15 amps

b

(1.1.6.1.3-1) The electrolyte used in a nickel-cadmium battery is distilled water and what other substance? (a) lead sulfate (b) potassium hydroxide (c) zinc oxide (d) diluted sulfuric acid

b

(1.1.6.1.3-3) What is the approximate voltage per cell produced by the nickel-iron (Edison) battery? (a) 0.85 volts (b) 1.37 volts (c) 2.20 volts (d) 6.05 volts

b

(1.1.7.1.1-1) As a DC armature revolves within a stationary magnetic field, the reversals of magnetization of the armature core lags the current reversals which produces heat. What is the correct name for this action which is minimized by the use of soft silicon steel? (a) eddy-current loss (b) hysteresis loss (c) capacitive reaction (d) copper loss

b

(1.1.10.1.2-1) How are fuses rated? (a) voltage and amperage only (b) interrupting capacity only (c) voltage, amperage, and interrupting capacity (d) amperage only

c

(1.1.10.1.2-5) What is the characteristic that is associated with an "instantaneous-trip" single- element type fuse? (a) opens a circuit by using a time delay element with a magnetic trip (b) allows a preset delay between overcurrent and melting (c) opens as soon as the load current exceeds its setpoint (d) resets itself when the overcurrent is corrected

c

(1.1.10.1.2-7) In a dual element time delay cartridge-type fuse, what type of protection is provided for motor applications? (a) short-circuit protection using a spring loaded soldered joint AND sustained overload protectionusing a fusible link (b) sustained overload protection using a spring loaded soldered joint only (c) short-circuit protection using a fusible link AND sustained overload protection using a springloaded soldered joint (d) short-circuit protection using a fusible link only

c

(1.1.13.1.1-10) What functionality does a low voltage protection circuit as used in electric motor starting equipment provide? (a) allow the motor to restart automatically on restoration of voltage without manually resetting (b) trip out the motor when the motor overspeeds due to low voltage (c) prevent the motor from restarting automatically on restoration of voltage (d) trip out the motor when the motor develops a short circuit due to low voltage

c

(1.1.14-3) At a minimum threshold, how many milliamps of current through the body produces a condition where most people would experience respiratory paralysis and be unable to breathe while still in contact with the energized conductor? (a) 3 to 7 mA (b) 10 to 16 mA (c) 30 mA (d) 75 mA for 5 sec.

c

(1.1.2.1-10) AC circuits can possess characteristics of resistance, inductance, and capacitance. In terms of units of measure, how is the capacitive reactance of the circuit expressed? (a) mhos (b) henrys (c) ohms (d) farads

c

(1.1.2.1-26) A direct current passing through a wire coiled around a soft iron core is known as what? (a) magnetic shield (b) electromagnetic domain (c) electromagnet (d) piezoelectric device

c

(1.1.2.1-8) What is the opposition to alternating current flow through a coil due to inductance called? (a) reactive inductance (b) impedance factor (c) inductive reactance (d) capacitive reactance

c

(1.1.2.3-5) Four lamps are connected in parallel in a single circuit. If one of the lamps burns out, what will happen to the other lamps? (a) become brighter (b) all go out (c) burn with their original intensities (d) become dimmer

c

(1.1.2.3-9) Which of the following statements concerning a circuit with parallel connected resistors is correct? (a) The total resistance equals the sum of the individual resistances. (b) The total current flow equals the reciprocal of the sum of the individual currents. (c) The voltage drop across each resistor is the same. (d) The total voltage equals the sum of the individual voltages across each resistance.

c

(1.1.3.1.1-2) Which of the following statements is true concerning all rotating-field three-phase alternators? (a) Each has three separate but identical, interconnected stator windings (one for each phase)acted on by three separate but identical, interconnected systems of rotating magnets (one for each phase). (b) Each has one stator winding acted on by three separate but identical, interconnected systems of rotating magnets (one for each phase). (c) Each has three separate but identical, interconnected stator windings (one for each phase)acted on by one system of rotating magnets. (d) Each has one stator winding acted on by one system of rotating magnets.

c

(1.1.3.1.1-6) Compared to conventional alternators, brushless alternators are designed to operate without the use of what? (a) voltage regulators (b) rectifiers (c) slip rings and commutators (d) exciters

c

(1.1.3.1.1-7) In a conventional AC generator utilizing brushes, direct current from the exciter output is passed through the windings of the main field rotor by what means? (a) by means of a commutator (b) by means of rotating bar magnet (c) by means of slip rings (d) to minimize the danger of arc over

c

(1.1.3.1.3-1) Which of the methods listed below is used to provide the rotational torque to cause an AC generator to turn? (a) Providing current to the field from an external source. (b) Residual magnetism remaining in the armature. (c) Starting of the prime mover. (d) Residual magnetism remaining in the field.

c

(1.1.3.1.3-3) Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. How are these changes in armature reaction compensated for? (a) phase-balance relay (b) governor speed droop setting (c) voltage regulator (d) balance coil

c

(1.1.3.1.3-6) The governor control switch of an alternator is moved to the 'raise' position. What will be the effect of this action? (a) raise the percentage of speed droop (b) lower the no-load speed setting of the governor (c) raise the no-load speed setting of the governor (d) lower the percentage of speed droop

c

(1.1.3.1.3-7) How will the value of the output frequency change if the load is removed from a turbo-generator having a governor speed droop setting of 3%? (a) It will decrease by approximately 3%. (b) It will remain unchanged. (c) It will increase. (d) It will become variable.

c

(1.1.3.2-1) With regard to the maintenance of electrical generating machines with insulated pedestal bearings, what practice should be avoided? o (a) cleaning and removing grease from the insulated area o (b) using a megohmmeter with the machine disassembled to determine insulation values • (c) painting or allowing grease build up on the insulated area o (d) touching the bearing shell while the machine running

c

(1.1.3.2-4) In performing routine maintenance of a ship's service alternator, what should be included? (a) lubricating exciter slip rings (b) megger testing of all rectifying diodes (c) periodic cleaning of the air filters or screens (d) changing the pedestal bearing insulation yearly

c

(1.1.4.2.3-2) If deck machinery is expected to be idle for an extended period of time, what should be done? (a) have electrical safety gloves available in case of electrical shock before running (b) perform a 'high pot' test to determine the condition of the insulation (c) energize space heaters to prevent the condensation of moisture (d) water wash the motor and controller to remove any salt that may interfere with smooth operation

c

(1.1.4.3.3-1) Which of the following conditions will occur if the brake solenoid coil burns out on a cargo winch with an electrical brake? (a) Nothing will happen; the winch will continue to operate as usual. (b) The motor will overspeed and burn up. (c) The brake will be set by spring force. (d) The load suspended from the cargo boom will fall.

c

(1.1.5.1-1) In a simple DC circuit, the resistance is held constant while the applied voltage is halved. What will be the effect on the current flow as compared to the original current? (a) double (b) remain the same (c) be divided by two (d) be divided by four

c

(1.1.5.1-5) What will be the resulting current when a voltage of 442.7 VDC is applied to a resistance of 1.25 ohms in figure "A" of the illustrated circuit when the switch is closed? Illustration EL-0018 (a) 28.25 amps (b) 35.32 amps (c) 354.16 amps (d) 443.62 amps

c

(1.1.5.1-7) What is the current flow through R1 of the circuit in figure "B" of the illustration with the switch closed if the resistance of R1 is 2 ohms, R2 is 3 ohms and R3 is 6 ohms and the battery voltage is 12 VDC? Illustration EL-0019 (a) 2 amps (b) 4 amps (c) 6 amps (d) 12 amps

c

(1.1.6.2.1-1) Which of the following statements concerning the specific gravity of a battery electrolyte is true? (a) The temperature does not affect the specific gravity of the electrolyte. (b) The most accurate hydrometer reading is obtained immediately after water is added. (c) The specific gravity reading is lowered when the electrolyte temperature has increased. (d) The electrolyte becomes less dense when it is cooled.

c

(1.1.6.2.1-3) Why should battery rooms be well ventilated during the charging process? (a) highly poisonous gas is produced (b) highly combustible oxygen gas is produced (c) highly explosive hydrogen gas is produced (d) corrosive gases are produced

c

(1.1.6.2.1-6) Why should a breakable, mercury-filled thermometer NOT be used in a lead-acid battery to measure electrolyte temperature? (a) accidental breakage can cause corrosion on the battery terminals (b) accidental breakage can cause rapid oxidation of battery plates (c) accidental breakage can cause severe sparking and explosions (d) accidental breakage can cause violent gassing at the positive plates

c

(1.1.8.2-4) What is an important factor in minimizing DC motor commutator wear? (a) ensuring a very low brush current density (b) keeping the ambient humidity as low as possible (c) establishing the copper oxide surface film (d) insuring that brush pressure is excessive

c

(1.1.10.1.2-4) Which of the following precautions should be taken when a blown fuse, rated at 10 amperes, is replaced? (a) Fuses of 10 ampere rating and less are virtually harmless when energized and may be handled freely. (b) Use needle-nose pliers to remove fuse from the circuit. (c) Short out the fuse before removing it from the circuit. (d) Replace blown fuse with one of equal voltage and ampere capacity.

d

(1.1.10.3.1-3) When maintenance personnel are working on electrical equipment, all supply switches should be secured in the open position and tagged. Who specifically should perform the lock-out/tag- out procedure? (a) chief electrician (b) chief engineer or first assistant (c) watch engineer (d) person performing the repair

d

(1.1.11.3.2-3) When troubleshooting electronic equipment, why should you use a high impedance multimeter? (a) for AC measurements only and a low resistance meter for DC measurements (b) whenever a low impedance meter is not available, regardless of the components being tested (c) to prevent excess current flow through the meter that would damage it (d) so as not to load down the circuit and obtain erroneous voltage readings

d

(1.1.12.5-1) Under what circumstance would a hand-held portable phase sequence indicator be used should the main switchboard mounted fixed phase sequence indicator be inoperative? (a) paralleling alternators (b) installing a new synchroscope (c) replacing a defective solenoid (d) preparing to make the shore power connection

d

(1.1.13.1.1-12) Which of the listed items will stop a motor due to a reduction in voltage and automatically restart it when the voltage is restored to normal? (a) Renewable link fuse (b) Non-renewable link fuse (c) Low voltage protection circuit (d) Low voltage release circuit

d

(1.1.13.1.1-6) A motor controller contains three selector push buttons labeled 'start', 'jog', and 'stop'. What will happen to the motor when the 'jog' button is depressed? (a) will run continuously after the 'jog' button is released (b) will not stop unless the 'stop' button is pushed (c) will not start until both the 'jog' and 'start' buttons are pushed (d) will run until the 'jog' button is released

d

(1.1.13.1.1-9) An electromagnetic relay is most commonly used for what purpose? (a) provide capacitance to a circuit (b) provide inductive power to a circuit (c) provide transformer secondary winding overcurrent protection (d) remotely open and close contacts by action of a coil

d

(1.1.14-4) At a minimum threshold, how many milliamps of current through the body produces a condition where most people would suffer ventricular fibrillation and could only be resuscitated with a ventricular defibrillator? (a) 3 to 7 mA (b) 10 to 16 mA (c) 30 mA (d) 75 mA for 5 sec.

d

(1.1.2.1-15) When placed in a magnetic field, which of the materials listed will maintain the highest permeability? (a) Bakelite (b) Aluminum (c) Glass (d) Soft iron

d

(1.1.2.1-3) What happens to the power loss when the current flow through a power transmission line is doubled? (a) it is divided by four (b) it is halved (c) it is doubled (d) it is quadrupled

d

(1.1.2.3-2) Which statement is true concerning the total power consumed in a parallel circuit? (a) The total power is never more than the power consumed by the largest load. (b) The total power is the sum of the powers consumed by each load (resistor) divided by the number of loads. (c) The total power is always less than the power consumed by the smallest load. (d) The total power is equal to the sum of the powers consumed by each individual load.

d

(1.1.3.1.1-5) Of the listed factors that influence the amount of RMS voltage induced in the windings of an AC generator operating at a constant 60 Hz frequency, which factor is variable during generator operation? (a) the number of armature coil turns in series per winding (b) the number of field coil turns in series per winding (c) the rotational speed at which the magnetic field passes across the stator winding (d) the strength of the rotating magnetic field

d

(1.1.3.1.3-5) When securing an AC generator, what should be your FIRST action in accomplishing the procedural steps? (a) decrease the field excitation to minimum (b) open the generator circuit breaker (c) switch the voltage regulator to 'manual' (d) reduce the load on the unit

d

(1.1.3.2-5) Which of the following statements, concerning the cleaning maintenance of a brushless generator, is correct? (a) High-pressure air should be used to blow out dust and grime from the windings. (b) Hot soapy water should be used to remove dust and grime from windings. (c) Cleaning of windings should be performed on a periodic basis regardless of the state of cleanliness. (d) Cleaning of windings should be performed on a conditional basis using a vacuum or using a clean, dry, lint-free rag.

d

(1.1.3.2-6) How may chattering of the collector/slip ring brushes on a generator be remedied? (a) increasing length of pigtail (b) re-insulating the brushes (c) lubricating brush holders (d) cleaning the collector rings with a canvas wiper

d

(1.1.3.2-7) Which of the following materials is recommended for burnishing the slip rings of an alternator after grinding or turning? (a) canvas wiper (b) smooth file (c) grade 00 sandpaper (d) hardwood block

d

(1.1.3.2-8) When an alternator is to remain idle for even a few days, what should be done? (a) lift the brushes and disconnect the pigtails (b) open the equalizing bus disconnect switch (c) insulate the collector rings with strips of cardboard (d) energize the space heater circuit

d

(1.1.4.2.3-1) As part of a routine maintenance program for deck machinery motor controllers, what should be done? (a) remove covers exposed to the weather and drain water each week (b) remove motor covers and ventilate as weather permits (c) check drum switch contact pressure every three months (d) inspect electrical wiring for evidence of corrosion or discoloration at connections

d

(1.1.6.1.1-2) The wet cell storage batteries shown in the illustration are connected in what configuration? Illustration EL-0070 (a) series (b) compound (c) tandem (d) parallel

d

(1.1.6.2.1-4) When a hydrometer indicates specific gravity what is being compared? (a) mass of substance measured with the density of the same substance (b) density of a substance in water with the density of the same substance in air (c) differences in weight between water and the mass of the liquid being measured (d) buoyancy of the indicator in the liquid being measured as compared to water

d

(1.1.8.2-1) What is the recommended method used to resurface an eccentric DC motor commutator? (a) burnish it with commutator stones (b) use a hard canvas wiper (c) use a hand stone (d) turn it down in the ship's lathe

d

(1.1.8.2-5) In general, what can cause DC propulsion motor brush sparking to be excessive? (a) a dark chocolate colored commutator (b) brushes positioned in the neutral plane (c) a concentric commutator (d) incorrect brush grade, pressure or position

d

(1.1.8.2-6) What should be included in performing proper maintenance of a DC motor's commutator? (a) painting the face of the commutator with insulating varnish (b) baking the armature in an oven at 350°C for 8 hours annually (c) coating the copper surface with light machine oil for the first four hours of operation (d) side-cutting the copper segments and undercutting the mica

d