Electricity & Electronics - QMED

The winch shown in the illustration will operate normally in all speeds in both directions, with the exception that it ...

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

When a hydrometer indicates specific gravity what is being compared?

Which of the following statements concerning the specific gravity of a battery electrolyte is true?

Why should battery rooms be well ventilated during the charging process?

Under normal conditions, storage batteries used for starting the emergency diesel- generator are maintained in a charged...

When a battery is continuously exposed to low temperatures, what is the best procedure to keep it from freezing? ...

Why should a breakable, mercury-filled thermometer NOT be used in a lead-acid battery to measure electrolyte temperature...

Compared to conventional alternators, brushless alternators are designed to operate without the use of what?

In a conventional AC generator utilizing brushes, direct current from the exciter output is passed through the windings ...

Why are space heaters provided on larger generators?

Of the listed factors that influence the amount of RMS voltage induced in the windings of an AC generator operating at a...

Which of the following statements is true concerning all rotating-field three-phase alternators?

For what purpose are time delayed or delayed action-type fuses used?

Which of the following precautions should be taken when a blown fuse, rated at 10 amperes, is replaced?

In a dual element time delay cartridge-type fuse, what type of protection is provided for motor applications?

In a single element cartridge-type fuse, what type of protection is provided for lighting and general power applications...

What is the characteristic that is associated with an "instantaneous-trip" single- element type fuse?

How would a circuit with a blown fuse be described?

How are fuses rated?

Multiple grounds have developed and were initially indicated by the ground-detecting system as one ground. What is the F...

When maintenance personnel are working on electrical equipment, all supply switches should be secured in the open positi...

Why must accidental grounds in a shipboard electrical system be repaired as soon as possible?

What is the name of the type of motor control circuit that will not permit automatic restarting after power is restored,...

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

An electromagnetic relay is most commonly used for what purpose?

What functionality does a low voltage protection circuit as used in electric motor starting equipment provide?

What is the functional name of an electrical device which prevents simultaneous energization of loads thereby preventing...

Which of the listed items will stop a motor due to a reduction in voltage and automatically restart it when the voltage ...

What operational characteristic is associated with the illustrated manual starter circuit for a motor shown in figure "A...

A motor controller contains three selector push buttons labeled 'start', 'jog', and 'stop'. What will happen to the mot...

Which of the following illustrated manual motor starters represents the wiring diagram illustrated in figure "A"? Illust...

Why are motor controllers seldom troubled with grounds?

The wet cell storage batteries shown in the illustration are connected in what configuration? Illustration EL-0070

The individual 6 volt lead-acid batteries, when connected as shown in the illustration, as a battery bank would produce ...

What should be the primary consideration when choosing a battery for a particular application?

Which of the following statements concerning a circuit with parallel connected resistors is correct?

Which of the following statements is true concerning circuits with parallel connected resistances?

Four lamps are connected in parallel in a single circuit. If one of the lamps burns out, what will happen to the other l...

Which statement is true concerning the total power consumed in a parallel circuit?

Which of the electrical properties listed will always be the same across each component in a parallel circuit?

What will happen to the total circuit resistance when additional parallel circuits are added to a circuit?

Which of the following devices would be forbidden to use as a primary means of electrical isolation?

At a minimum threshold, how many milliamps of current through the body produces a condition where most people would expe...

After prior isolation and lock-out/tag-out procedures are performed, which electrical device requires discharging any st...

Before electrical work can be safely undertaken, the equipment must be de-energized, locked and tagged out, and verifica...

At a minimum threshold, how many milliamps of current through the body produces a condition where most people would suff...

Which of the following voltage testers would be associated with high quality, be safe to use, and minimize the electric ...

With all other factors considered equal (such as voltage, conducting path through the body and the duration of contact),...

At a minimum threshold, how many milliamps of current through the body produces a condition where most people would be u...

At a minimum threshold, how many milliamps of current through the body produces a painful sensation that most people wou...

As part of a routine maintenance program for deck machinery motor controllers, what should be done?

If deck machinery is expected to be idle for an extended period of time, what should be done?

In performing routine maintenance of a ship's service alternator, what should be included?

With regard to the maintenance of electrical generating machines with insulated pedestal bearings, what practice should ...

Which of the following statements, concerning the cleaning maintenance of a brushless generator, is correct?

Rotor-to-stator air gap readings should be periodically taken for electrical generation equipment. What is the best tool...

When an alternator is to remain idle for even a few days, what should be done?

How may chattering of the collector/slip ring brushes on a generator be remedied?

Which of the following materials is recommended for burnishing the slip rings of an alternator after grinding or turning...

In general, what can cause DC propulsion motor brush sparking to be excessive?

What should be included in performing proper maintenance of a DC motor's commutator?

What is an important factor in minimizing DC motor commutator wear?

What is the recommended method used to resurface an eccentric DC motor commutator?

When troubleshooting a lead-acid storage battery, what is the best method for detecting a weak or dead cell?

As a DC armature revolves within a stationary magnetic field, the reversals of magnetization of the armature core lags t...

Under what circumstance would a hand-held portable phase sequence indicator be used should the main switchboard mounted ...

Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a correspond...

The governor control switch of an alternator is moved to the 'raise' position. What will be the effect of this action? ...

How is the frequency of an alternator at a given RPM determined?

Which of the methods listed below is used to provide the rotational torque to cause an AC generator to turn?

How are the number of cycles per second developed by the alternator aboard your vessel determined?

How is the power factor of an AC generator operating singularly determined?

How will the value of the output frequency change if the load is removed from a turbo- generator having a governor speed...

What is the most practical way to control the voltage output of an AC generator?

When securing an AC generator, what should be your FIRST action in accomplishing the procedural steps?

What is the current flow through R1 of the circuit in figure "B" of the illustration with the switch closed if the resis...

In a simple DC circuit, the resistance is held constant while the applied voltage is halved. What will be the effect on...

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 ...

What would be the total current flowing in the circuit shown in figure "B" of the illustration if the source is 30 volts...

If the voltage supplied to the lighting circuit is 110 volts, how much current is drawn by a 100 watt light bulb?

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...

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...

What would be the indication of a burned-out LED?

Which of the following conditions would most likely lead to the failure of a resistor due to overheating?

When troubleshooting electronic equipment, why should you use a high impedance multimeter?

What is the approximate voltage per cell produced by the nickel-iron (Edison) battery?

In general, why are nickel-cadmium storage batteries superior to lead-acid batteries?

The electrolyte used in a nickel-cadmium battery is distilled water and what other substance?

What is the opposition to alternating current flow through a coil due to inductance called?

What will happen to an electrical coil when the direct current flowing through the coil is increasing?

The resistance of most conducting materials will change as a result of temperature change. What will happen to the resis...

How does the resistance of a conductor vary?

What is the name of the force that causes free electrons to flow in a conductor producing electric current?

A direct current passing through a wire coiled around a soft iron core is known as what?

AC circuits can possess characteristics of resistance, inductance, and capacitance. In terms of units of measure, how is...

What happens to the power loss when the current flow through a power transmission line is doubled?

What property does capacitance have in an AC circuit?

What is the correct name for current that flows in only one direction?

When placed in a magnetic field, which of the materials listed will maintain the highest permeability?

Which of the following statements concerning AC circuits is correct?

Which of the formulas listed is correct for determining power?

In the flow of one cycle of single phase alternating current past any given point in a circuit, how many times will the ...

What is the combined effect of inductive reactance, capacitive reactance, and resistance in an alternating current circu...

The existing resistance of a conductor is dependent upon its length, cross-sectional area, and what other factors?

Alternating current circuits may develop resistance, inductance, and capacitance. What is the unit of measure for expre...

The number of cycles per second occurring in AC voltage is known as what characteristic?

In terms of units, how is the inductance of a coil measured?

In a three-phase circuit, how far apart are the phase voltages?

The term "volt" describes:

What is the unit of measure for electrical resistance?

If a DC motor runs faster than designed, with all other conditions being normal, what could be the possible cause?

If a DC motor runs hot, what would most likely be the cause?

Besides a condition of overload, what could be a cause of an open armature connection in a DC propulsion motor?

Besides for checking for circuit continuity, what can an ohmmeter be used for in diagnosing a DC motor?

What would excessive sparking at the brushes of a running DC motor be an indication of?

In addition to improper brush pressure or seating, what can result in excessive sparking at the brushes of a DC propulsi...

If a short circuit in the armature of a DC motor occurs what would be the result?

An open in the armature of a DC motor is suspected, but is not found by visual inspection of the commutator. What would ...

Which of the listed colors properly describes a DC motor commutator when correct commutation is taking place?

What can insufficient brush pressure on a DC motor cause?

How is a short in the shunt field of a DC motor best located?

One method of testing for a reversed shunt field coil in a DC motor is by connecting the coil to a low voltage source, a...

What is the most effective method of locating a loose commutator bar in a DC motor?

How can a shorted armature coil in a DC motor be detected?

How may temporary repairs to an open DC propulsion armature coil be made, allowing continued operation until permanent r...

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars?

If an unloaded DC compound motor's shunt field were weakened by excessive rheostat resistance or by an open circuit, how...

In a short-shunt cumulatively compound-wound DC motor, how is the shunt field connected?

Why are motor controllers seldom troubled by grounds?

Which device will stop the motor shown in the illustration in case of a short-circuit (high current) motor fault? Illus...

In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 5 reads line voltage, w...

If you hear a loud buzzing noise coming from a magnetic motor controller, what should you do?

The motor starts when the start button in the illustration is pushed, but stops when the button is released. What is mos...

The motor fails to start on an attempted startup. With the start button depressed, a voltmeter reading between 1 and 5, ...

The illustrated motor fails to start and gives a loud hum when the start button is depressed, what should then be your f...

What can be the cause of excessive heat or burning contacts in an operating motor controller?

A capacitor is to be tested with a digital multimeter set up to measure ohms. If the meter is connected to a shorted cap...

If a digital multimeter is set up as shown in figure "A" of the illustration to test a capacitor, what would the display...

What should be done with a capacitor that is obviously discolored due to excessive heat?

If a digital multimeter is set up as shown in figures "A" and "B" to test a silicon diode, what is the status of the dio...

If a digital multimeter is set up as shown in figures "A" and "B" of the illustration, what is the status of the silicon...

As shown in the illustration, what maintenance would be required of the circuit components? Illustration EL-0058

If the centrifugal switch or relay used for cutting out the starting winding of a split- phase induction motor fails to ...

A single-phase capacitor-start induction motor starts, comes up to about 75% rated speed, slows down to a lower speed, a...

A digital multimeter is set up as shown in the illustration to evaluate the single-circuit stator windings of a squirrel...

By what means is the burning of controller contacts due to arcing, when opening, prevented?

As shown in figure "B" of the illustration, when the DC motor in figure "A" is operating at minimum speed what are the a...

As shown in the illustrated electrically operated watertight door controller, how is the rotation direction of the door ...

In the illustrated views of a lead-acid battery as shown in figures "A" and "B", what battery component has the sole fun...

How many cells are within a 24 volt lead-acid battery?

The nominal open-circuit voltage of one cell of a fully charged lead-acid battery is approximately how many volts?

What controls rudder movement when the Operation Selector Switch shown in figure "A" of the illustration is in the "Con...

As shown in figure "A" of the illustration, fine adjustments such as "rate of turn signal" have no effect on steering st...

Before measuring an unknown resistance with an analog multimeter set up as an ohmmeter, what should you do?

What is an ohmmeter used to measure?

As shown in figure "A" of the illustrated digital multimeter screen, what would be the significance of the symbol indica...

A digital multimeter is set up as an ohmmeter on the 1 kilo ohm scale. What does a display reading of 'OL' ohms as read ...

If the approximate voltage to be measured in an electric circuit is not known, what should be done?

In troubleshooting a circuit in a console, you find that a resistor may be faulty. Which of the precautions listed must ...

If a digital multimeter set up to measure AC volts reads slightly above 'zero' when its leads are disconnected, what is ...

Which of the following precautions should be taken when troubleshooting various power circuits using a digital multimete...

Circuit resistance is usually measured off-line (de-energized) with an ohmmeter. In the absence of an ohmmeter, however,...

Whether analog or digital, what are most AC voltmeters calibrated to measure?

Which of the meters listed should only be used after a circuit has been electrically de-energized?

What practice could potentially damage a multimeter?

Which of the listed statements is correct when using a digital multimeter set up as an ohmmeter?

What should be done when performing maintenance of circuit breaker contacts?

What device can be used to check the calibration of a circuit breaker?

When working on electrical circuits containing large capacitors, in addition to de-energizing the circuit, which of the ...

Which of the following statements represents the FIRST precaution to be taken prior to working on any installed electric...

What is the proper way to apply plastic electrical tape to an electric cable splice?

When working on a high voltage circuit, you should always have another person present with you. This person should have ...

Why is motorization of an AC generator undesirable?

An alternator is being paralleled with one already on the line. At the INSTANT the incoming generator circuit breaker is...

An alternator switchboard has a synchroscope and synchronizing lamps. If the synchroscope is broken, which of the steps ...

Diesel-generators number 1 and number 2 are operating in parallel at near full load capacity. Diesel-generator number 1 ...

What is the purpose of a ship's service generator circuit breakers reverse power trip?

If field excitation is suddenly lost to an alternator operating in parallel with another alternator, what will happen to...

When paralleling two AC generators, the synchroscope selector switch and frequency meter switch should be set up to sens...

What will happen when a loss of field excitation to an AC generator occurs while operating in parallel?

What should be the frequency of the incoming machine when paralleling two AC generators immediately prior to closing it...

When paralleling two alternators, the synchronizing lamps remain lit as the synchroscope pointer approaches the 0°. What...

What governor settings are the load sharing characteristics of two diesel-generators operating in parallel mostly depend...

Attempting to parallel an AC generator which is out of phase with the bus will result in which of the following conditio...

Which of the following statements is true concerning the operation of two alternators in parallel?

You are paralleling two alternators. The synchronizing lamps grow dim and are totally darkened as the synchroscope point...

You are attempting to parallel two AC generators, and the synchroscope pointer is revolving in the fast direction. What ...

To remove an alternator operating in parallel with another unit from the main electrical bus, what must be done FIRST? ...

A main switchboard synchronizing panel is fitted with two synchronizing lamps and a synchroscope. When paralleling, if t...

If the excitation of an alternator operating in parallel is decreased below normal and the other above normal, what will...

When paralleling two alternators using three synchronizing lamps, the flickering of all three lamps becomes progressivel...

You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. What wo...

After closing the circuit breaker to place two alternators with identical ratings in parallel, in terms of achieving a b...

What device is used so that the kilowatt load sharing can be adjusted on paralleled generators?

As shown in figure "1" of the illustration, a correctly connected synchronous transmission causes the receiver to be in ...

As shown in the illustrated wiring diagram for an engine order telegraph system, what statement concerning the constant ...

If it is required that the coils 'R1-R2-R3' in the indicator of figure "A", turn opposite to those in the transmitter, a...

What determines the direction of rotation of an AC induction motor?

With respect to motors, how is ambient temperature defined?

What will be the impact of reduced voltage applied to an AC induction motor during the starting period?

Which of the illustrated motors has a totally enclosed, fan-cooled (TEFC) motor enclosure? Illustration EL-0001 ...

As shown in figure “A" of the illustrated motor nameplate, what is the service factor at sea level? Illustration EL-0171...

Which of the following statements is true concerning the operating characteristics of a basic squirrel-cage induction mo...

In a basic AC induction motor, by what means are rotor currents induced in the rotor?

In a three-phase, squirrel-cage type, induction motor, how is the primary rotating magnetic field established?

What type of motor is illustrated by the schematic of figure "B" of the illustration and what type of starting relay is ...

In a 15 HP induction-type motor with a squirrel-cage rotor, compared to the full load current at rated speed, how much s...

Which of the pictured motors is a square core shaded pole motor used to drive very small electrical loads and is non-rev...

With respect to electrical enclosure types, how may an electric motor be designed and constructed?

One item listed on the nameplate of a cargo pump motor is 'degrees centigrade rise.' What does the number stamped for th...

Which of the illustrated motors has a totally enclosed motor enclosure? Illustration EL-0001

If an induction motor were to be operated at 90% rated voltage and at rated load, what would be the result?

Which of the following motors has a frame configuration for resilient base mounting? Illustration EL-0184

What operational information data appears on the nameplates of shipboard AC motors?

What type of motor enclosure is utilized for the motor labeled "A" of the illustration? Illustration EL-0001

A 125 volt DC motor is rated at 10 kW. What is the current rating of the motor?

What is the wattage of a heating element drawing a current of 30 amperes, at 120 volts?

A three-phase alternator operates at 450 volts with a 0.8 power factor. If the ammeter indicates 250 amperes, what shoul...

How many watts of power is equal to one horsepower?

How is the power dissipated as heat in a direct current circuit calculated?

Two 100 watt light bulbs rated at 100 volts are connected in parallel across a 100 volt power supply. What will be the t...

What power would be consumed by the series resistor in the circuit shown in the illustration if the source is 30 volts, ...

In order to safely carry out repairs to a generator circuit breaker; it must be isolated from the bus. How is this accom...

Assuming a standard 60 Hz input to the circuit shown in the illustration, what would be the ripple frequency? Illustrati...

What does the drawing in the illustrated circuit represent? Illustration EL-0063

What is the direction of electron current through the load resistor in the circuit shown in the illustration? Illustrati...

In figure "A" of the illustrated circuit, what is the main purpose of the bias resistor Rb? Illustration EL-0045

What is the correct name for the device used in an electrical circuit to change alternating current to direct current? ...

What type of feedback is featured in the transistor amplifier shown in figure "B" of the illustration assuming that the ...

Which section of the circuit shown in the illustration smoothes out highest degree of pulsations? Illustration EL-0085 ...

In the regulated DC power supply illustrated, what is the function of section "B"? Illustration EL-0085

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

What is the function of section "D" of the circuit shown in the illustration? Illustration EL-0085

Which of the referenced waveshapes would appear at test point 5 (TP5

Capacitors are commonly used on DC power supply circuits for engine room automation consoles. For what functional purpos...

The component labeled 'CR1' in the circuit shown in the illustration serves what functional purpose? Illustration EL-008...

What is the total resistance of figure "B" of the illustrated circuit if the resistance of R1 is 3 ohms, R2 is 4 ohms, a...

What statement is true concerning the total power consumed in a series circuit?

Which of the following statements is correct for the illustrated circuit in figure "B"? Illustration EL-0020

What is true concerning all of the connecting conductors of a DC series circuit?

What happens to the current in a series circuit when the voltage remains constant and the resistance increases?

The torque produced by a DC motor armature is the multiplication product of two factors, one being the density of the ma...

In DC motor construction, with regard to the individual armature coils' ends, which statement is true?

What is the function of the commutator associated with a DC motor?

In DC motor construction, where are the commutating windings wound?

Which of the following statements describes what will happen when both the polarity of the field poles, and the directio...

The counter EMF of a DC motor is maximum when the _______________.

What will happen if you reverse both the field and the armature connections of a DC propulsion motor?

What is an advantage of DC motors over AC motors?

Why are the armature cores of the DC motors constructed with laminated steel sheets?

What is the characteristic of the mica used in the commutators of DC machinery?

If overloading an electric motor becomes necessary in an emergency situation, what should be done to prevent damage to t...

What is the name of the DC motor speed control method utilized as shown in figure "B" of the illustration? Illustration...

In terms of voltage potential and current sources, how are shunt wound, series wound, and compound-wound DC motors desig...

As shown in the illustrated DC machine which is configured as a generator, what is the purpose of the interpoles? Illust...

What is the function of the interpoles installed in DC motors?

What is the item referred to as a pigtail on a DC motor brush rigging?

What statement is true concerning a ground in a 450 VAC electrical circuit outside the engine room?

Capacitors can be used in electric distribution systems to improve power factor. This is accomplished by seesawing ener...

What is meant by a 'dead front' switchboard?

What is a bus disconnect link used to isolate?

How are the line losses in a distribution circuit kept to a minimum?

Which of the following represents a characteristic of an ungrounded electrical distribution system?

When will the timer element of a reverse power relay activate the relay?

In comparison to a main switchboard for a DC electrical distribution system, a main switchboard for an AC electrical dis...

Ammeters and voltmeters used in sinusoidal AC power systems indicate which of the following values of the waveforms meas...

What is a purpose of the automatic bus transfer device shown in the illustration? Illustration EL-0014

What is a wattmeter used to measure and indicate?

What is the name of the part of the shipboard electrical system used to control the distribution of power to the branch ...

How may propulsion DC motor brush pressures be calculated?

Brushes in a DC generator must be positioned in the neutral plane to avoid excessive sparking associated with the brushe...

To effectively clean a commutator in good physical condition, what should be used?

What could cause a very slow, but continual loss of electrolyte level from the cells of a storage battery?

Concerning the illustrated fire detection and alarm system, what statement is true concerning the wiring between zones? ...

What is the characteristic of a wound-rotor induction motor with maximum rheostat resistance inserted in the rotor circu...

As shown in the illustrated wound-rotor induction motor, how is the direction of rotation of the motor reversed? Illustr...

What is the characteristic of a wound-rotor induction motor, with a high resistance inserted in series with the rotor wi...

For what purpose is the variable resistance placed in the rotor circuit of a wound- rotor induction motor provided? ...

Which of the following materials is a good electrical insulator?

How is electrical conductor insulation classed? Example: insulation class H

Which of the waveshapes shown in the illustration is termed a ramp or sawtooth wave? Illustration EL-0088

To minimize magnetic field interaction between electrical conductors in physical proximity, what is the best practice? ...

The multiplier prefix 'giga' (G) such as used in "gigabytes" represents what multiplication factor?

In electronic circuitry, what does the abbreviation 'PCB' commonly represent?

Which line in figure "B" shown in the illustration represents the trailing edge of the wave? Illustration EL-0088

When troubleshooting AC motors, what can a portable growler be used to locate?

When testing the rotor of a synchronous motor for short circuits, a low voltage source is applied across the rotor coils...

In using a portable growler for the purpose of locating a shorted stator coil in an AC motor as shown in the illustratio...

What is an ammeter used to measure?

In order to take a current reading with a 'clamp-on' ammeter, what should be the status of the jaws of the instrument? ...

The clamp-on AC ammeter consists essentially of a split-core and a rectifier-type instrument connected to the secondary ...

What should be included in the performance of routine maintenance of dry-type transformers?

When replacing a defective transformer in a paralleled transformer configuration, which of the following actions must be...

What can cause uneven wear of the commutator surface on a direct current generator?

What may cause brush sparking in a DC generator during commutation?

Hysteresis is one cause of electrical power loss associated with electricity generation equipment. What phenomenon resul...

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

Which of the following represents the accepted method of cleaning dust and foreign particles from electrical equipment w...

What damage may occur to the components of a winch master control switch, if the cover gasket becomes deteriorated? ...

Before working on an electric cargo winch master switch or controller, what should be done?

In the illustration shown, what type of protection is provided to the potable pump drive motor? Illustration EL-0043 ...

Low horsepower, polyphase, induction motors can be started with full voltage by means of which kind of starter? ...

As shown in the illustration, which of the following conditions will occur as a result of a momentary loss of power? Ill...

In the illustration shown, what would be the functional name for the coil represented as '1S'? Illustration EL-0012 ...

If the line voltage to the controller shown in the illustration is 440 volts, what is applied across the control circuit...

As shown in the illustration, if the line voltage is 450 VAC, what would be the applied voltage to the motor at the inst...

A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices w...

What type of starter is represented in the electrical schematic shown in the illustration? Illustration EL-0017

As shown in the illustration of the elementary diagram of a three speed anchor windlass controller, which of the followi...

How is the reversal of an AC, three-phase, induction motor accomplished?

When a motor is started by the controller shown in figure "C" of the illustration, what circuit components are in the ho...

Which of the following statements is true concerning the motor controller circuit shown in the illustration? Illustratio...

As shown in the illustration, what is the purpose of the main contacts of contactor "2S"? Illustration EL-0012

As shown in the illustration, what type of starter is illustrated? Illustration EL-0104

What is the primary functional purpose of the KM1 contactor as shown in the illustration? Illustration EL-0080

As shown in figure "B" of the illustration, which of the operations listed will happen when the 'jog button' is pushed? ...

In the illustrated motor controller, what do the contacts across terminals "3" and "4" of the control circuit represent...

Referring to figure "B" of the illustrated control circuit schematic diagram, which of the following statements is true ...

As shown in the illustration, assuming power is available at the control circuit, which listed action will occur FIRST w...

What type of control circuit logic is featured in the electrical schematic diagram for the motor starting circuit shown ...

In the system shown in the illustration, the engine room station is unable to signal any other station, nor is any other...

Why are external shunts sometimes used with ammeters?

What is the instrument called a galvanometer used to measure?

When a resistor is used as a shunt and is connected in parallel with a meter movement coil, what capability does this pr...

To limit the current flow through a DC voltmeter to as low a value as possible, what is the moving coil circuit provided...

Which of the listed meters uses a shunt connected in series with the load, but parallel with the meter movement? ...

Which of the following would best describe a standard electric meter movement that uses the principles of electromagneti...

An internal resistance is placed in series with the meter movement of which of the following instruments?

Which of the electronic schematic symbols represents the capacitor illustrated in figure 2 of the illustration? Illustra...

Which of the illustrated schematic symbols represents the type of switch pictured in figure "F" of the illustration? Ill...

What is the shape of the schematic symbol for an operational amplifier used in an analog circuit?

Which figure represents the schematic symbol shown in figure "2"? Illustration EL-0034

Which of the illustrated resistors represents the schematic symbol shown in figure "C"? Illustration EL-0021

Which electrical schematic symbol represents a normally open thermostat? Illustration EL-0059

As shown in figure "6" of the illustration, what does the symbol represent as used in electrical drawings? Illustration ...

The electrical diagram shown in figure “B” of the illustration represents what type of DC motor? Illustration EL-0054 ...

What is statement is true in reference to reading electrical motor controller elementary diagrams?

What does the symbol labeled "OL" represent as shown in the power circuit on lines T1 and T3 to the motor as shown in fi...

What type of electrical diagram is shown in figure "B" of the illustration? Illustration EL-0007

Which of the listed figures in the illustration represents a transformer configured for single voltage primary and a tap...

When troubleshooting an alkaline storage battery, what is the best way to locate a weak or dead cell?

In terms of the battery electrolyte, when performing maintenance of alkaline batteries what should be done?

If the pointer fails to return to zero when a hand-cranked megger is disconnected, what does this indicate?

Two contributors of electronic console failures are heat and vibration. To combat some of their effects, what should be ...

Which of the following statements represents the important factor that must be considered when replacing a faulty diode ...

If a delicate component must be soldered into a circuit, how can the component be protected from the heat of the solderi...

Which type of flux should be used when soldering electrical wire connections for electronic components on printed circui...

Before touching a small capacitor connected to a de-energized circuit, or even one that is completely disconnected, you ...

An AC generator produces 60 Hz at 1800 RPM. If the generator speed is increased to 1830 RPM, what will happen to the fr...

What is the rotor speed of a six pole, 60 cycle, induction motor operating at full load with 3% slip?

A four pole turbo-generator is used in conjunction with a 160 pole propulsion motor. If the generator is turning at 3,20...

In a 60 Hz AC system, what is the duration in seconds for one complete cycle?

As shown in figure "A" of the illustration if the applied voltage is 12 VDC, the resistance of R1 is 10 ohms, and R2 is ...

What would be the voltage drop across the parallel branches of the circuit shown in figure "B" of the illustration if th...

A battery is connected to a circuit containing three resistors in parallel. The values of the three resistors are 2 ohms...

In the illustration, 1, 2, 3 and 4 are 12 volt batteries. What will be the nominal voltage as read by a voltmeter across...

What is the voltage across 'R1' of figure "B" of the illustrated circuit with the switch closed if the applied voltage i...

If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller control circuit illustra...

A triac thyristor functions as a control device and can be thought of to function similarly as which of the following ci...

What is the name of the component labeled Q1 as shown in section "D" of the regulated DC power supply illustrated? Illus...

When a solid-state component of an electronic circuit is mounted to a metallic mass, what is the general purpose of that...

As shown in the illustrated electronic overload relay circuit, what is the functional purpose of potentiometer "R2"? Ill...

Which of the pictured solid-state semiconductor devices in the illustration is a rectifier bridge? Illustration EL-0068 ...

Basically, a magnetic amplifier is a saturable-core reactor with the addition of what additional feature?

What will happen to a carbon resistor operating in electrical equipment that is NOT properly cooled?

What is the name of the semiconductor that decreases in resistance with an increase in temperature?

The characteristics of the device shown in figure "8" of the illustration includes a stable voltage and low current whil...

Although saturable reactors are extremely useful in some applications, why is their gain low?

Grease coatings on electrical contact surfaces increase contact resistance. How should grease accumulations be removed? ...

Which of the following statements is true concerning the cleaning of electrical contacts?

The setpoint current at which a magnetic-type overload relay tends to trip may be increased by turning the dashpot in th...

Which of the following methods should be used to dress the face of silver-plated contacts?

Using the catalog selection chart shown in Illustration EL-0180, determine the correct catalog number for a motor starte...

Where is the power necessary to energize the howler "relay" coil at the engine room station as shown in the illustration...

As shown in the illustration, which of the following statements is correct concerning the circuits in a sound-powered te...

The push button on the handset of a ship's sound-powered telephone must be depressed in order to do what?

What does the component labeled "B" shown in the illustration represent? Illustration EL-0093

Which statement is true concerning a split-phase induction motor?

What type of rotor is used in the split-phase family of single-phase motors?

Universal motors will operate on AC or DC current. In what application is this type of motor generally?

What is the main purpose of the auxiliary winding on a split-phase, single-phase motor?

What is the main function in the use of a capacitor for starting a single-phase motor?

Within the split phase family of single phase motors, what are the operational characteristics of the motor shown in fig...

As shown in figures "A", "B", "C", and "D" of the illustration, what is the usual means by which the rotation direction ...

Of the following listed single-phase induction motors, which has the highest starting torque?

Which of the pictured motors within the split phase family of single phase induction motors represents a capacitor start...

If the illustrated device in figure "B" has a step-up ratio of 10 to 1 what voltage would be measured at the secondary s...

An open primary coil in a simple potential transformer will be indicated by which of the listed conditions?

What would be the source current and transformer current as shown in figure "B" of the illustration, with the secondary ...

The torque-speed and current-speed curves for a three-phase induction motor with a squirrel cage rotor are shown in figu...

In general, what type of starter would be used to connect polyphase induction motors to full line voltage at the instant...

Autotransformer starters, sometimes called starting compensators, are sometimes used with larger polyphase induction mot...

According to the sample sheet of a typical "List of Motors and Controls" as shown in the illustration, which of the foll...

The progressive operation of the contactors marked "1A" through "4A" provide the winch hoist controller shown in the ill...

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

As shown in the illustration, what is the functional purpose of the normally closed and normally open auxiliary contacts...

What is the function of the electric brake on a deck cargo winch?

What functionality do the 'MS 1' contacts of the master switch shown in the illustration provide? Illustration EL-0102 ...

Which of the listed conditions occur when '4th point lower' is selected on the winch hoist controller shown in the illus...

When the control handle is in the 'off' position, what is the status of the solenoid actuated brake of an electric winch...

Incandescent lamps are classified according to the shape of the bulb and the type of service, as well as the size and st...

As shown in the illustration, what event would give the same indication that would occur when a stern light circuit fuse...

What type of circuit is represented by the diagram shown in the illustration? Illustration EL-0058

As shown in the illustration, what are the characteristics of the trouble relay contacts? Illustration EL-0058 ...

As shown in the illustration, the change-over switch is what type of device? Illustration EL-0058

Which of the listed types of lighting fixtures does the diagram shown in figure "A" of the illustration represent? Illus...

As shown in the illustration, which of the lighting fixtures represents an incandescent bulb? Illustration EL-0122

What is the functional purpose of component "5" as shown in figure "B" of the illustration? Illustration EL-0081

What is the purpose of the capacitor within component "5" of the circuit shown in figure "B" of the illustration? Illust...

Besides the fluorescent lamp itself and possibly a starter, which of the following components is included in a fluoresce...

What would you use to determine the state of charge of a nickel-cadmium battery?

Which of the following statements concerning nickel-cadmium batteries is true?

When a nickel-cadmium battery begins gassing while connected to the battery charging circuit, what should be done?

Which statement is true concerning the charging of a wet cell nickel-cadmium battery?

When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately. If not, what conditio...

As shown in the wiring diagram of the semi-automatic navigation lighting panel circuit, what would cause the buzzer to s...

When a fluorescent lamp fails to light and both ends of the tube are severely darkened, what must usually be replaced? ...

What is indicated by gradual blackening at the ends of component "4" shown in figures "B" and "C" of the illustration? I...

What may be the cause of an AC generator to fail to produce a voltage?

If a shipboard AC generator experiences a failure to produce a voltage, what may be the cause?

How can the loss of residual magnetism in an alternator or generator be corrected?

An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and mak...

If coil 'R1-R2-R3' on the transmitter in figure "C" shown in the illustration is turned 30 degrees clockwise, how will t...

In actual applications, electrical connections associated with 'R1, R2 and R3' of the transmitter to 'R1, R2, and R3' of...

In the circuit 'B' of the illustration, what would be the result of the upper heating element being burned out and open ...

For more complete vessel protection when using an impressed current cathodic system, what other features are built into ...

Impressed current cathodic hull protection systems are commonly used on modern vessels. What are these systems designed ...

What should be done when correcting specific gravity readings of a lead-acid battery for existing temperature conditions...

When charging lead-acid batteries, why should you reduce the charging rate as the battery nears its full charge capacity...

When charging, which of the following represents the recommended maximum allowable temperature for electrolyte in a lead...

When charging a 100 amp-hour lead-acid battery, what statement is true?

What is the most reliable indication of the state of charge of a lead-acid battery?

What is the proper way to mix the electrolyte for a lead-acid battery?

What will the charging of lead-acid storage batteries always result in?

What can cause the pitting or welding of controller contacts?

If a magnetic controller contact fails to pick up when the operating coil is energized, what could be one possible cause...

When troubleshooting a magnetic controller, it is found that the contacts are welded together. What is the most probable...

If the motor shown in the illustration will not start when the "off-run" switch is placed in the run position, which of ...

As shown in figure "C" of the illustrated typical ground fault sensor, what statement concerning its installation is tru...

When troubleshooting a motor controller, all indications are that a relay coil should be energized. If there was no magn...

If many turns of an alternating current coil for a contactor become short-circuited, what will happen to the coil? ...

As shown in figure "A" and "B" of the illustration, the potable water pump is short- cycling by the action of the pressu...

If a magnetic controller relay fails to drop out when the coil voltage is removed from the relay, what is the probable c...

You are troubleshooting the control circuit shown in figure "A" of the illustration utilizing on-line techniques. With t...

A loud buzzing noise coming from the contacts in a magnetic controller can be caused by what condition?

If a digital multimeter is set up as shown in figure "A" of the illustration to test an AC contactor coil, what would t...

What is a common type of protective covering used on electrical conductors?

What is the reason that some electric cables are formed of stranded wire?

Which of the illustrated safety disconnect switches represents a double-throw switch? Illustration EL-0176

Why is copper often used as an electrical conductor?

Which of the following statements concerning electrical cables is correct?

As shown in the illustrated one-line diagram of a two-tiered emergency power system for a passenger ship, what statement...

The 24 volt DC bus on the emergency switchboard is used to supply power to what system or equipment?

Which of the following characteristics is most critical in determining the wire gauge size of the cable to be used in a ...

As shown in the illustration, which of the following pieces of equipment is provided with a remote push button station? ...

What is the function of the autotransformers used with autotransformer starters used on some large AC motors?

What is the primary purpose associated with the use of transformers onboard ships with AC generators?

If the primary winding of a voltage transformer is connected to a steady DC source, self-inductance and mutual inductanc...

Which of the listed transformers uses a single winding to produce voltage transformation?

Which of the following statements is true concerning step-down transformer operation?

When a transformer is used to step-down voltage, what statement is true?

Which of the schematic symbols shown in the illustration represents a normally closed float level switch? Illustration E...

Which of the listed figures shown in the illustration represents a three phase transformer connected in a wye-delta conf...

Which of the following statements is true concerning a step-down transformer in an operating AC power circuit?

What is the purpose for the device shown in figure "B" of the illustration in terms of its relationship with the load? I...

What is the basic operating principle of a transformer in terms of producing a voltage?

Which of the following is a pictured three phase power transformer, usually used to step-down line voltage for supplying...

What will happen to the primary winding when the load increases on the secondary windings of a transformer?

When a low input voltage is delivered to a transformer which then produces a high output voltage, what is the proper nam...

Which of the following statements describes the difference between the primary windings and the secondary windings of a ...

What is the purpose of a potential transformer in an electric circuit?

As shown in the illustrated plots of uncorrected and temperature corrected insulation resistance readings for a particul...

What is the resistance reading at "2" on the megger scale shown in figure "A" of the illustration? Illustration EL-0044 ...

When performing routine AC motor maintenance what should be included?

By periodically checking the stator-to-rotor air gap clearance in an induction motor with a feeler gauge, what is preven...

Which of the following statements represents the FIRST step in seating new brushes on slip rings?

For what reason should engine room watchstanders keep a constant check on the loads carried by electric motors?

What is a useful instrument for checking 3 phase AC motor performance by measuring possible unbalanced currents? ...

If a three-phase induction motor is operated under a light load and it develops an open in one of its supply lines, what...

In testing a three-phase delta-connected winding for an open circuit using a ohmmeter, what must be done?

Which of the following methods should be used to test for an 'open' stator winding coil in a wye-connected AC squirrel c...

If a single-phase capacitor start induction motor fails to start, but instead hums without starting, what is most likely...

As shown in figure "B" of the illustration, with a digital multimeter set up as an ohmmeter, what set of readings would ...

When replacing a fuse with one of a ampere higher rating than the original, which of the following is true?

To test fuses in an energized circuit, what testing apparatus or meter should be used?

What would cause a fuse to blow?

In order to definitively determine whether or not fuse "2", shown in the illustration is blown using an on-line testing ...

What type of DC motor is never connected to a belt driven load?

In a series wound motor, the current passing through the field windings also passes through what component?

What is the most common source of excitation for the rotor of a synchronous motor utilizing slip rings and brushes? ...

An increase in which of the listed conditions will increase the speed of a synchronous electric motor?

What causes the rotor of a synchronous motor to operate in synchronism with the rotating field?

What is the function of the squirrel cage windings installed on a synchronous motor rotor?

By what means does a molded-case circuit breaker provide protection against short circuits?

How does a circuit breaker differ from a fuse?

By what means is protection against sustained overloads occurring in molded-case circuit breakers provided?

How can a motor be protected from overheating due to sustained motor overload?

A thermal-magnetic circuit breaker for a 300 kW alternator is rated at 500 amperes at full continuous load. Which of the...

When the operating handle of a molded-case circuit breaker is in the mid-position, what is the indication for the positi...

Undervoltage trips are frequently installed on switchboard circuit breakers for what reason?

How will a molded-case circuit breaker with a thermal trip unit react immediately after it has tripped, as a result of a...

When replacing fuses, what practice should be observed?

When changing fuses, what safety precaution should be taken?

When two generators are on the line and are both connected across a shared load, how are they said to be operating? ...

By what means is an AC generator prevented from becoming motorized?

What is the main purpose of an electric space heater installed in a large AC generator?

When shore power is being connected to a ship in drydock, what must be ensured, assuming that the ship's generators are ...

The amount of voltage induced in the stator windings of a modern AC generator is primarily dependent upon which of the f...

How are AC and DC generators similar?

In which figure shown in the illustration will the highest voltage be induced? Illustration EL-0028

As shown in the illustration, which brush holder would be appropriate to use in a bidirectional motor? Illustration EL-0...

By what means is a diesel-driven emergency generator prevented from being paralleled with the ship's service generators?...

A DC generator which is used to supply direct current in order to provide magnetizing current to an AC generator field i...

Upon failure of the ships normal electrical power supply, by means of what device does the emergency generator supply po...

When would be the safest time to close the ship's main switchboard "shore power" circuit breaker?

With what device is the RPM of an AC generator indirectly measured on a switchboard when operating singly (no other gene...

The turns ratio of the step-down transformer with dual voltage secondary as shown in figure "B" of the illustration is t...

In figure "2" of the diagram shown in the illustration, the three phase power transformer has a step-down turns ratio of...

What is the maximum allowable primary current of a 2 kVA step-down transformer with a four to one turns ratio if the pri...

A load is connected across the secondary of the step-up transformer shown in figure "B" of the illustration and the curr...

As load is added to a DC shunt motor, how will the motor respond?

In an ungrounded distribution system, as compared to a normal indication, what is the indication on a switchboard of a c...

A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected. What is this caused by?...

In a three-phase electrical system, three ground detecting lamps are provided. One lamp goes dark and the others increas...

If all of the ground detection lamps burn with equal brilliance, whether the test button is depressed or released, what ...

A three-phase electrical system is equipped with ground detecting lamps. If one of the lamps is dark, and remains dark w...

Which of the terms listed best describes a compound-wound DC generator having a higher voltage at no load than at full l...

By what means is DC generator output voltage decreased?

Which of the following components are used to convert alternating current produced in the DC generator armature windings...

As shown in the illustrated DC machine which is configured as a generator, what type of machine is illustrated in terms ...

What is the primary purpose of the brushes of DC generators?

In a shunt-wound DC generator, with what generator component are the shunt field windings connected in parallel with? ...

A variable shunt, connected across the series field coils of a DC compound wound generator, permits adjustment of the de...

As shown in the illustration, which brush holder is of the reaction type? Illustration EL-0029

Which of the diagrams shown in the illustration depicts the proper method of aligning brushes on a commutator for a DC m...