In a diesel electric plant, raising the generator's field excitation will cause the DC propulsion motor to ________. A. increase in speed B. decrease in speed C. affect generator speed only D. affect main motor speed if done in conjunction with higher generator engine speeds

In a diesel electric plant, raising the generator's field excitation will cause the DC propulsion motor to ________. A. increase in speed B. decrease in speed C. affect generator speed only D. affect main motor speed if done in conjunction with higher generator engine speeds
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On some diesel-electric ships, the DC propulsion motor will only attain half speed when the generator fields are fully excited. Speeds above this are obtained by _____________. A. rotating brush alignment B. raising the generator engine speed C. lowering the generator engine speed D. decreasing excitation

Description : On some diesel-electric ships, the DC propulsion motor will only attain half speed when the generator fields are fully excited. Speeds above this are obtained by _____________. A. rotating brush ... B. raising the generator engine speed C. lowering the generator engine speed D. decreasing excitation

Last Answer : Answer: B

Electric propulsion coupling excitation is reduced at slow speeds to ___________. A. increase speed control B. increase shaft torque C. prevent coupling overheating D. prevent coupling slippage

Description : Electric propulsion coupling excitation is reduced at slow speeds to ___________. A. increase speed control B. increase shaft torque C. prevent coupling overheating D. prevent coupling slippage

Last Answer : Answer: C

In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength

Description : In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength

Last Answer : Answer: A

A four pole turbogenerator is used in conjunction with a 160 pole propulsion motor. If the generator is turning at 3,200 RPM, what is the current speed of the propeller? A. 40 RPM B. 60 RPM C. 80 RPM D. 100 RPM

Description : A four pole turbogenerator is used in conjunction with a 160 pole propulsion motor. If the generator is turning at 3,200 RPM, what is the current speed of the propeller? A. 40 RPM B. 60 RPM C. 80 RPM D. 100 RPM

Last Answer : Answer: C

Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator rotors will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.

Description : Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator ... will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.

Last Answer : Answer: A

An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. cause the slip rings to melt C. cause a low voltage differential to develop between the armature and the bus D. cause high currents to be induced in the field windings

Description : An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. ... between the armature and the bus D. cause high currents to be induced in the field windings

Last Answer : Answer: D

The propeller shaft speed in a turbo-electric, synchronous, propulsion drive motor is changed by varying the __________. A. turbine speed B. number of motor poles C. field strength of the generator D. field strength of the motor

Description : The propeller shaft speed in a turbo-electric, synchronous, propulsion drive motor is changed by varying the __________. A. turbine speed B. number of motor poles C. field strength of the generator D. field strength of the motor

Last Answer : Answer: A

On a vessel with turbo-electric drive, which of the following conditions would indicate that the propulsion motor had dropped out of synchronization with the propulsion generator? A. Excessive vibration of the vessel B. Tripped main motor interlocks C. Overheated crosstie busses D. Closed contact in the field circuits

Description : On a vessel with turbo-electric drive, which of the following conditions would indicate that the propulsion motor had dropped out of synchronization with the propulsion generator? A. Excessive ... Tripped main motor interlocks C. Overheated crosstie busses D. Closed contact in the field circuits

Last Answer : Answer: A

Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Description : Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Last Answer : Answer: D

The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Description : The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: A

The power factor at which a paralleled AC generator operates is usually adjusted by the _____________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Description : The power factor at which a paralleled AC generator operates is usually adjusted by the _____________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: C

To increase the frequency of an operating AC generator, you should ____________. A. increase the field excitation B. decrease the field excitation C. increase the number of magnetic poles D. increase the speed of the prime mover

Description : To increase the frequency of an operating AC generator, you should ____________. A. increase the field excitation B. decrease the field excitation C. increase the number of magnetic poles D. increase the speed of the prime mover

Last Answer : Answer: D

Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions properly and trips generator #1 electrically off the bo A. Start the emergency generator. B. Ascertain cause of the low lube oil pressure. C. Strip the board of all nonvital circuits. D. Secure alarms, reset reverse power relay, and restart #1 engine.

Description : Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions ... all nonvital circuits. D. Secure alarms, reset reverse power relay, and restart #1 engine.

Last Answer : Answer: C

Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency controllers D. permit higher voltage for electric motor operation and low voltage for lighting circuits

Description : Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency ... D. permit higher voltage for electric motor operation and low voltage for lighting circuits

Last Answer : Answer: D

Which of the listed devices may be installed on a large diesel-electric alternating current propulsion generator? A. Temperature detector coils inserted in the stator slots for measuring stator temperature. B. A CO2 fire extinguishing system. C. Electric space heaters to prevent condensation of moisture. D. All of the above.

Description : Which of the listed devices may be installed on a large diesel-electric alternating current propulsion generator? A. Temperature detector coils inserted in the stator slots for measuring stator temperature. B. ... . C. Electric space heaters to prevent condensation of moisture. D. All of the above.

Last Answer : Answer: D

The voltage developed by an AC generator is controlled by varying the ____________. A. speed of the prime mover B. AC excitation to the field C. DC excitation to the field D. DC excitation of the voltage regulator

Description : The voltage developed by an AC generator is controlled by varying the ____________. A. speed of the prime mover B. AC excitation to the field C. DC excitation to the field D. DC excitation of the voltage regulator

Last Answer : Answer: C

Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Description : Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Last Answer : Answer: A

The prime mover of an AC two pole main propulsion generator drives the generator at 3600 RPM. If the main propulsion motor has 80 poles, what will be the propeller speed? A. 45 RPM B. 80 RPM C. 90 RPM D. 180 RPM

Description : The prime mover of an AC two pole main propulsion generator drives the generator at 3600 RPM. If the main propulsion motor has 80 poles, what will be the propeller speed? A. 45 RPM B. 80 RPM C. 90 RPM D. 180 RPM

Last Answer : Answer: C

The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________. A. provide excitation to the DC field B. start the machine as an induction motor C. contribute extra torque at synchronous speed D. prevent the machine from falling out of step

Description : The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________. A. provide excitation to the DC field B. start the machine as an induction motor C. contribute extra torque at synchronous speed D. prevent the machine from falling out of step

Last Answer : Answer: B

A loss of field excitation to an AC generator while operating in parallel will cause it to ____________. A. absorb more and more load due to decreased armature reaction B. lose its load due to the inherent speed droop built into the governor C. smoke and overload due to field flashover as residual field flux changes polarity D. lose its load, begin to motorize, trip out on reverse power relay, and possibly overspeed

Description : A loss of field excitation to an AC generator while operating in parallel will cause it to ____________. A. absorb more and more load due to decreased armature reaction B. lose its load due to ... polarity D. lose its load, begin to motorize, trip out on reverse power relay, and possibly overspeed

Last Answer : Answer: D

The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator

Description : The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator

Last Answer : Answer: C

The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply

Description : The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply

Last Answer : Answer: C

The purpose of DC generator brushes is to _____________. A. neutralize armature reaction B. conduct electric current to an outside circuit C. convert DC current to AC current D. provide excitation to a DC generator

Description : The purpose of DC generator brushes is to _____________. A. neutralize armature reaction B. conduct electric current to an outside circuit C. convert DC current to AC current D. provide excitation to a DC generator

Last Answer : Answer: B

An open armature connection in a DC propulsion motor could be caused by ____________. A. low-load operation B. clogged ventilation ducts C. sparking at the brushes D. a grounded shunt field coil

Description : An open armature connection in a DC propulsion motor could be caused by ____________. A. low-load operation B. clogged ventilation ducts C. sparking at the brushes D. a grounded shunt field coil

Last Answer : Answer: B

The direction of rotation of a DC propulsion motor can be changed by reversing the _____________. A. brush holder position B. polarity of the field poles C. brush staggered order D. motor interpole connections

Description : The direction of rotation of a DC propulsion motor can be changed by reversing the _____________. A. brush holder position B. polarity of the field poles C. brush staggered order D. motor interpole connections

Last Answer : Answer: B

If you reverse both the field and the armature connections to a DC propulsion motor, _____________. A. the direction of motor rotation will change B. the brushes will become overheated C. a magnetic lock will occur in the motor D. the direction of motor rotation will remain the same

Description : If you reverse both the field and the armature connections to a DC propulsion motor, _____________. A. the direction of motor rotation will change B. the brushes will become overheated C. a magnetic lock will occur in the motor D. the direction of motor rotation will remain the same

Last Answer : Answer: D

The direction of rotation of a DC propulsion motor can be reversed by __________. A. reversing the field connections B. reversing the field and the armature connections C. wiring the field and armature in parallel D. wiring the field and armature in series

Description : The direction of rotation of a DC propulsion motor can be reversed by __________. A. reversing the field connections B. reversing the field and the armature connections C. wiring the field and armature in parallel D. wiring the field and armature in series

Last Answer : Answer: A

When starting a DC propulsion motor the variable rheostat must FIRST be turned ____________. A. all the way to the run position then quickly back to slow B. to the slow position then gradually moved to full speed C. to the mid position D. quickly to the run position

Description : When starting a DC propulsion motor the variable rheostat must FIRST be turned ____________. A. all the way to the run position then quickly back to slow B. to the slow position then gradually moved to full speed C. to the mid position D. quickly to the run position

Last Answer : Answer: B

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.

Description : 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.

Last Answer : Answer: A

When securing an AC generator, you should FIRST ___________. A. open the generator circuit breaker B. switch the voltage regulator to 'manual' C. decrease the field excitation to minimum D. reduce the load on the unit

Description : When securing an AC generator, you should FIRST ___________. A. open the generator circuit breaker B. switch the voltage regulator to 'manual' C. decrease the field excitation to minimum D. reduce the load on the unit

Last Answer : Answer: D

An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically equalize the power factors C. reverse the direction of current in the series field of the incoming generator D. parallel the series fields of the generators

Description : An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically ... the series field of the incoming generator D. parallel the series fields of the generators

Last Answer : Answer: D

If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel; the generator rotor may be periodically pulled ahead or behind its normal position as it rotates. This hu A. amortisseur windings B. direct coupling C. increase governor speed droop D. decreasing governor speed droop

Description : If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel; the generator rotor may be periodically pulled ... windings B. direct coupling C. increase governor speed droop D. decreasing governor speed droop

Last Answer : Answer: A

A synchronous motor maintains synchronism with the rotating field because _____________. A. field strength varies directly with rotor slip B. DC current applied to the rotor coils causes the rotor magnets to lock in with the rotating flux of the stator C. the stator poles are dragged around due to the flux created by the excitation current D. the stator flux rotates in the opposite direction

Description : A synchronous motor maintains synchronism with the rotating field because _____________. A. field strength varies directly with rotor slip B. DC current applied to the rotor coils causes the rotor ... the flux created by the excitation current D. the stator flux rotates in the opposite direction

Last Answer : Answer: B

A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of the machine as a motor will be (A) 800 rpm. (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.

Description : A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of ... . (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.

Last Answer : (C) less than 800 rpm.

A hysteresis motor (A) is not a self-starting motor. (B) is a constant speed motor. (C) needs dc excitation. (D) can not be run in reverse speed.

Description : A hysteresis motor (A) is not a self-starting motor. (B) is a constant speed motor. (C) needs dc excitation. (D) can not be run in reverse speed.

Last Answer : (B) is a constant speed motor

While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates the _____________. A. motor has started properly B. field windings are grounded C. slip rings are dirty D. power transmission cables are grounded

Description : While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates the _____________. A. motor has started ... field windings are grounded C. slip rings are dirty D. power transmission cables are grounded

Last Answer : Answer: A

The standard method of controlling the output voltage of a 440 volt, 60 Hz, AC generator is accomplished by adjusting the ____________. A. prime mover speed droop B. number of poles C. alternator field excitation D. load on the alternator

Description : The standard method of controlling the output voltage of a 440 volt, 60 Hz, AC generator is accomplished by adjusting the ____________. A. prime mover speed droop B. number of poles C. alternator field excitation D. load on the alternator

Last Answer : Answer: C

If two AC generators have just been placed in parallel, the true power load is initially distributed evenly by _____________. A. a balance coil B. changing field excitation C. adjusting the governor control settings D. a rheostat

Description : If two AC generators have just been placed in parallel, the true power load is initially distributed evenly by _____________. A. a balance coil B. changing field excitation C. adjusting the governor control settings D. a rheostat

Last Answer : Answer: C

Sparking at the brushes of a DC propulsion motor can be the result of ____________. A. improper brush pressure B. improper brush seating C. reversed interpole polarity D. all of the above

Description : Sparking at the brushes of a DC propulsion motor can be the result of ____________. A. improper brush pressure B. improper brush seating C. reversed interpole polarity D. all of the above

Last Answer : Answer: D

Propulsion DC motor brush pressures can be calculated by _____________. A. dividing the brush contact area by the spring pressure B. subtracting the brush contact area from the spring pressure C. dividing the spring force by the brush contact area D. subtracting the spring pressure from the brush contact area

Description : Propulsion DC motor brush pressures can be calculated by _____________. A. dividing the brush contact area by the spring pressure B. subtracting the brush contact area from the spring pressure C. ... force by the brush contact area D. subtracting the spring pressure from the brush contact area

Last Answer : Answer: C

Which of the listed devices may be installed on a large turbo-electric alternating current propulsion generator? A. Temperature detector coils inserted in the stator slots for measuring stator temperature. B. A CO2 fire extinguishing system. C. Electric space heaters to prevent condensation of moisture. D. All of the above.

Description : Which of the listed devices may be installed on a large turbo-electric alternating current propulsion generator? A. Temperature detector coils inserted in the stator slots for measuring stator temperature. B. A ... . C. Electric space heaters to prevent condensation of moisture. D. All of the above.

Last Answer : Answer: D

Moving the rheostat handle shown in the illustration, that is used to control a DC generator, towards the 'raise' direction will increase the _____________. EL-0030 A. field resistance B. armature resistance C. armature speed D. line voltage

Description : Moving the rheostat handle shown in the illustration, that is used to control a DC generator, towards the 'raise' direction will increase the _____________. EL-0030 A. field resistance B. armature resistance C. armature speed D. line voltage

Last Answer : Answer: D

A diesel driven emergency generator is prevented from being paralleled with the ship's service generators by __________. A. an electrical interlock system B. an automatic paralleling trip switch C. the synchronizing oscilloscope D. the reverse current relay

Description : A diesel driven emergency generator is prevented from being paralleled with the ship's service generators by __________. A. an electrical interlock system B. an automatic paralleling trip switch C. the synchronizing oscilloscope D. the reverse current relay

Last Answer : Answer: A

Which of the following statements is true concerning a polyphase 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.

Description : Which of the following statements is true concerning a polyphase synchronous propulsion motor? A. The motor is started as an induction motor. B. Resistance is gradually added to the rotor circuit. C. ... is held below the rated current. D. The field winding is energized for starting purposes only.

Last Answer : Answer: A

The effect of carrying field excitation excessively high on a synchronous motor will result in a _____________. A. tendency for the motor to fall out of step B. tendency for the motor to overspeed C. tendency for the motor to overheat D. loss of motor speed regulation

Description : The effect of carrying field excitation excessively high on a synchronous motor will result in a _____________. A. tendency for the motor to fall out of step B. tendency for the motor to overspeed C. tendency for the motor to overheat D. loss of motor speed regulation

Last Answer : Answer: C

The speed of a synchronous motor is varied by _____________. A. interchanging any two of the three live leads B. changing the voltage of the system C. changing the input frequency D. increasing the field excitation

Description : The speed of a synchronous motor is varied by _____________. A. interchanging any two of the three live leads B. changing the voltage of the system C. changing the input frequency D. increasing the field excitation

Last Answer : Answer: C