In testing a three-phase delta winding for an open circuit using a megohmmeter, you must ______________. A. test each phase with all connections intact B. measure the voltage across the open connections while testing C. test the windings as parallel groups to avoid short circuiting D. open the delta-connections to avoid shunting the phase being tested

In testing a three-phase delta winding for an open circuit using a megohmmeter, you must ______________. A. test each phase with all connections intact B. measure the voltage across the open connections while testing C. test the windings as parallel groups to avoid short circuiting D. open the delta-connections to avoid shunting the phase being tested
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Answer: D
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If you obtain a low resistance reading with a megohmmeter connected between terminals 'A' and 'C' of the three-phase, wye-connected winding shown in the illustration, there is __________. EL-0074 A. no open circuit between 'A' and 'C' B. no open circuit between 'C' and 'B' C. an open circuit between 'A' and 'C' D. an open circuit in both windings

Description : If you obtain a low resistance reading with a megohmmeter connected between terminals 'A' and 'C' of the three-phase, wye-connected winding shown in the illustration, there is __________. EL-0074 A. no open circuit ... 'B' C. an open circuit between 'A' and 'C' D. an open circuit in both windings

Last Answer : Answer: A

Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test as the ______________. A. insulation may be damaged B. insulation may be covered with moisture C. armature windings will have a greater number of leakage paths D. larger machines may acquire a charge of static electricity during operation

Description : Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test as the ______________. A. insulation may be damaged ... number of leakage paths D. larger machines may acquire a charge of static electricity during operation

Last Answer : Answer: D

When using a megohmmeter to determine which shunt field coil is grounded in a DC machine, you must ____________. A. insulate the field frame from the ship's hull B. disconnect each shunt field coil before testing C. use a motor driven high capacity megohmmeter D. remove all main line lead connections before testing

Description : When using a megohmmeter to determine which shunt field coil is grounded in a DC machine, you must ____________. A. insulate the field frame from the ship's hull B. disconnect each shunt ... C. use a motor driven high capacity megohmmeter D. remove all main line lead connections before testing

Last Answer : Answer: B

One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for polarity using a/an ____________. A. iron bar across each field B. magnetic compass placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections

Description : One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for ... placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections

Last Answer : Answer: B

Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test, because the ___________. A. static charge of the machine may give a false reading B. armature will have a greater number of leakage paths C. insulation may be damaged D. insulation may be covered with moisture

Description : Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test, because the ___________. A. static charge of the machine ... number of leakage paths C. insulation may be damaged D. insulation may be covered with moisture

Last Answer : Answer: A

A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across each field coil C. using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter

Description : A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across ... using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter

Last Answer : Answer: B

In a simple series circuit, the entire source voltage will drop across ______________. A. the resistor next to the negative terminal B. a short circuit C. the resistor next to the positive terminal D. an open circuit

Description : In a simple series circuit, the entire source voltage will drop across ______________. A. the resistor next to the negative terminal B. a short circuit C. the resistor next to the positive terminal D. an open circuit

Last Answer : Answer: D

Which of the following actions must be carried out before a voltage tester can be used to test the three line fuses to a three-phase motor? A. The fuses must be removed from the circuit. B. The starter must be placed in the STOP position to stop the motor. C. The three line connections in the motor terminal box must be disconnected and tagged. D. Nothing need be done as long as the motor is running under a light load.

Description : Which of the following actions must be carried out before a voltage tester can be used to test the three line fuses to a three-phase motor? A. The fuses must be removed from the circuit. B. The ... disconnected and tagged. D. Nothing need be done as long as the motor is running under a light load.

Last Answer : Answer: B

You are using a mechanical voltage tester to check the fuses in a three-phase circuit supplying an electric motor. For which of the following reasons must the motor be stopped during the test? A. Testing an energized circuit presents a hazard to the testing personnel. B. A faulty fuse could go undetected with the motor energized. C. Reversed polarity of the circuit would be indicated by the voltage tester with the circuit energized. D. All of the above.

Description : You are using a mechanical voltage tester to check the fuses in a three-phase circuit supplying an electric motor. For which of the following reasons must the motor be stopped during the test? A. ... circuit would be indicated by the voltage tester with the circuit energized. D. All of the above.

Last Answer : Answer: B

In the illustrated test, if the lamp fails to light on any of the three windings then _________. EL-0027 A. all three windings are grounded and the motor should be sent out for repair B. the brushes should be set back on the commutator and the test redone C. the ground is not in the windings and the connections to the motor controller and the controller should be checked D. the test should be redone at a higher voltage

Description : In the illustrated test, if the lamp fails to light on any of the three windings then _________. EL-0027 A. all three windings are grounded and the motor should be sent out for repair B. ... the motor controller and the controller should be checked D. the test should be redone at a higher voltage

Last Answer : Answer: C

The amount of voltage induced in the windings of an AC generator depends on ____________. A. the number of conductors in series per winding B. the speed at which the magnetic field passes across the winding C. the strength of the magnetic field D. all of the above

Description : The amount of voltage induced in the windings of an AC generator depends on ____________. A. the number of conductors in series per winding B. the speed at which the magnetic field passes across the winding C. the strength of the magnetic field D. all of the above

Last Answer : Answer: D

When using a megohmmeter to test the dielectric strength of wire insulation, a continuous series of slight downscale kicks by the pointer is result of ____________. A. good insulation B. the leakage of current along the surface of dirty insulation C. the capacitance of the windings D. the dielectric-absorption effect of the insulation

Description : When using a megohmmeter to test the dielectric strength of wire insulation, a continuous series of slight downscale kicks by the pointer is result of ____________. A. good insulation B. the ... dirty insulation C. the capacitance of the windings D. the dielectric-absorption effect of the insulation

Last Answer : Answer: B

An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and observing a ____________. A. negative deflection of the wattmeter pointer B. positive deflection of the wattmeter pointer C. buildup of alternator voltage D. low, but constant alternator voltage

Description : An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and observing a ____________. A. negative deflection of the wattmeter pointer B. ... of the wattmeter pointer C. buildup of alternator voltage D. low, but constant alternator voltage

Last Answer : Answer: C

You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, becoming fairly steady as the leakage current stabilizes B. remain constant as the temperature of the windings increases C. continue to drop as the potential is maintained, becoming fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation

Description : You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, ... fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation

Last Answer : Answer: A

In a capacitor start single-phase induction motor, the capacitor is connected (A) in series with main winding. (B) in series with auxiliary winding. (C) in series with both the windings. (D) in parallel with auxiliary winding.

Description : In a capacitor start single-phase induction motor, the capacitor is connected (A) in series with main winding. (B) in series with auxiliary winding. (C) in series with both the windings. (D) in parallel with auxiliary winding.

Last Answer : Ans: B To make single phase motor self start. We split the phases at 90 degree. Hence, motor behaves like a two phase motor.

A megohmmeter is connected to each end of an individual motor winding. A low ohm reading indicates ____________. A. an open coil B. a loose coil C. good continuity D. a dirty coil

Description : A megohmmeter is connected to each end of an individual motor winding. A low ohm reading indicates ____________. A. an open coil B. a loose coil C. good continuity D. a dirty coil

Last Answer : Answer: C

Periodic testing by a shoreside support technician using a special camera which can detect potentially dangerous loose or corroded bus bar and controller connections is termed ______________. A. heat sensitive thermography B. visual pyrotronics C. corrosion electrolysis D. electric vibroanalysis

Description : Periodic testing by a shoreside support technician using a special camera which can detect potentially dangerous loose or corroded bus bar and controller connections is termed ______________. A. heat sensitive thermography B. visual pyrotronics C. corrosion electrolysis D. electric vibroanalysis

Last Answer : Answer: A

To carry out an insulation resistance test, one terminal of the megohmmeter should be connected to the winding, with the other terminal being connected to the ____________________. A. power supply B. variable resistor C. frame of the machine D. armature

Description : To carry out an insulation resistance test, one terminal of the megohmmeter should be connected to the winding, with the other terminal being connected to the ____________________. A. power supply B. variable resistor C. frame of the machine D. armature

Last Answer : Answer: C

For practical purposes, in a simple series circuit, the source voltage will be dropped across one resistor if it has ______________. A. half the resistance of the other resistor B. a resistance equal to the other C. at least ten times the resistance of the other D. a partial short circuit

Description : For practical purposes, in a simple series circuit, the source voltage will be dropped across one resistor if it has ______________. A. half the resistance of the other resistor B. a resistance equal to the other C. at least ten times the resistance of the other D. a partial short circuit

Last Answer : Answer: C

Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one armature winding acted on by three identical but separate systems of rotating magnets. C. All three-phase alternators are designed to operate with a 0.8 leading power factor. D. The three phases always provide power to the load through three sets of slip rings and brushes.

Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.

Last Answer : Answer: A

A device which can be used to check the calibration of a circuit breaker is a _________________. A. 500 volt megohmmeter B. portable low voltage high current testing unit C. standard digital multimeter D. clamp-on voltmeter

Description : A device which can be used to check the calibration of a circuit breaker is a _________________. A. 500 volt megohmmeter B. portable low voltage high current testing unit C. standard digital multimeter D. clamp-on voltmeter

Last Answer : Answer: B

When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then _________________. A. make sure wired connections and push-on connectors are tight B. test each resistor and capacitor on the card with an ohmmeter C. check the continuity of all printed circuit traces with an ohmmeter D. measure the gain of each transistor or integrated circuit

Description : When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then _________________. A. make sure wired connections and push-on connectors ... circuit traces with an ohmmeter D. measure the gain of each transistor or integrated circuit

Last Answer : Answer: A

In a three-phase electrical system, three ground detecting lamps are provided. If all three lamps REMAIN at half-brilliance when the ground detecting test switch is operated, ______________. A. there is a slight ground on all three phases B. the switch must be replaced C. there are no grounds present D. the light bulbs are of improper voltage

Description : In a three-phase electrical system, three ground detecting lamps are provided. If all three lamps REMAIN at half-brilliance when the ground detecting test switch is operated, ______________. A. there is a ... must be replaced C. there are no grounds present D. the light bulbs are of improper voltage

Last Answer : Answer: C

One important difference between wye-connected and delta-connected generators is that delta connections have ____________. A. line voltages equal to the vector sum of the phase voltages B. phase voltages 90° out of sync C. line current equal to the phase current D. line voltage equal to the phase voltage

Description : One important difference between wye-connected and delta-connected generators is that delta connections have ____________. A. line voltages equal to the vector sum of the phase voltages B. phase voltages 90° ... C. line current equal to the phase current D. line voltage equal to the phase voltage

Last Answer : Answer: D

Temporary repairs to an open DC propulsion armature coil can be made by _____________. A. connecting the coil ends directly to a pair of negative brushes B. disconnecting coil ends, insulating each, and short circuiting the two commutator bars C. grounding the coil ends and short circuiting the commutator bar D. removing the sparking brushes

Description : Temporary repairs to an open DC propulsion armature coil can be made by _____________. A. connecting the coil ends directly to a pair of negative brushes B. disconnecting coil ends, insulating ... C. grounding the coil ends and short circuiting the commutator bar D. removing the sparking brushes

Last Answer : Answer: B

When a megohmmeter is used to test the insulation of a large motor, the initial dip of the pointer toward 'zero' is caused by ____________. A. good insulation B. the capacitance of the windings C. the leakage of the current along the surface of dirty insulation D. the dielectric-absorption effect of the insulation

Description : When a megohmmeter is used to test the insulation of a large motor, the initial dip of the pointer toward 'zero' is caused by ____________. A. good insulation B. the capacitance of the ... of the current along the surface of dirty insulation D. the dielectric-absorption effect of the insulation

Last Answer : Answer: B

When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the leakage of current along the surface of dirty insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Description : When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the ... insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Last Answer : Answer: D

The function of fuse in an electrical circuit is (a) avoid electric shocks (b) regulate the flow of current (c) break the circuit in case of overloading or short circuiting (d) switch off current

Description : The function of fuse in an electrical circuit is (a) avoid electric shocks (b) regulate the flow of current (c) break the circuit in case of overloading or short circuiting (d) switch off current

Last Answer : Ans:(c)

When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across the top of the first line fuse and the bottom of the third line fuse C. apply the voltage tester across the bottoms of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester

Description : When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across ... of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester

Last Answer : Answer: D

The synchronous reactance of the synchronous machine is ______________. (A) Ratio between open circuit voltage and short circuit current at constant field current (B) Ratio between short circuit voltage and open circuit current at constant field current (C) Ratio between open circuit voltage and short circuit current at different field current (D) Ratio between short circuit voltage and open circuit current at different field current

Description : The synchronous reactance of the synchronous machine is ______________. (A) Ratio between open circuit voltage and short circuit current at constant field current (B) Ratio between short circuit ... (D) Ratio between short circuit voltage and open circuit current at different field current

Last Answer : Ans. A The Synchronous reactance of a synchronous machine is a total steady state reactance, presented to applied voltage, when rotor is running synchronously without excitation. Therefore , XS = Ef / IS = Emf of OC for same If / short circuit current

A capacitor can be tested using a megohmmeter or an ohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance value for the capacitor B. first swing quickly to 'zero', then gradually move up the scale as the capacitor charges C. immediately deflect to and remain at zero D. immediately swing to a high reading and then gradually decrease

Description : A capacitor can be tested using a megohmmeter or an ohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance ... deflect to and remain at zero D. immediately swing to a high reading and then gradually decrease

Last Answer : Answer: C

A low voltage source is being used for testing armature coils. A coil short circuit will be indicated by a _______. A. high voltage reading, while the other coil readings will have an equal or lower value B. low or zero voltage reading, while the other coils will have higher readings C. fluctuating voltmeter reading, while the other coil readings are steady D. steady voltmeter reading, while the other coil readings are fluctuating

Description : A low voltage source is being used for testing armature coils. A coil short circuit will be indicated by a _______. A. high voltage reading, while the other coil readings will have an ... the other coil readings are steady D. steady voltmeter reading, while the other coil readings are fluctuating

Last Answer : Answer: B

[75] Two transformers are connected in parallel. These transformers do not have equal percentage impedance which results A. Short-circuiting of the secondaries B. Power factor of one of the transformers is leading while that of the other lagging C. Transformers having higher copper losses will have negligible core losses D. Loading of the transformers not in proportion to their kVA ratings.

Description : [75] Two transformers are connected in parallel. These transformers do not have equal percentage impedance which results A. Short-circuiting of the secondaries B. Power factor of one of the ... have negligible core losses D. Loading of the transformers not in proportion to their kVA ratings.

Last Answer : D. Loading of the transformers not in proportion to their kVA ratings

To test fuses in an energized circuit, you should use a ____________. A. low voltage light bulb B. megohmmeter C. voltmeter D. resistance meter

Description : To test fuses in an energized circuit, you should use a ____________. A. low voltage light bulb B. megohmmeter C. voltmeter D. resistance meter

Last Answer : Answer: C

Before servicing the device indicated as 'A' in panels #1 and #3 of the illustration, the device labeled 'CT' must __________. EL-0003 A. have the disconnected leads taped to prevent short circuiting. B. only be connected to multimeter on the ammeter setting C. be short circuited D. have one lead grounded to discharge static electricity for the prevention of damage to electronic components

Description : Before servicing the device indicated as 'A' in panels #1 and #3 of the illustration, the device labeled 'CT' must __________. EL-0003 A. have the disconnected leads taped to prevent ... D. have one lead grounded to discharge static electricity for the prevention of damage to electronic components

Last Answer : Answer: C

If your multimeter gives a reading in ohms when testing each end of each conductor of a three-conductor cable, this indicates ______________. A. continuity of the conductor B. an infinite resistance C. the presence of a partial ground D. that the conductor is not short circuited

Description : If your multimeter gives a reading in ohms when testing each end of each conductor of a three-conductor cable, this indicates ______________. A. continuity of the conductor B. an infinite resistance C. the presence of a partial ground D. that the conductor is not short circuited

Last Answer : Answer: A

An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from _____________. A. one line terminal to each coil lead in succession B. one field coil to each adjacent field coil in turn C. any suitable ground to any available line lead D. any field pole to each field coil lead

Description : An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from ... C. any suitable ground to any available line lead D. any field pole to each field coil lead

Last Answer : Answer: A

Consider the following statements regarding three-phase transformers in Open -Delta (V -V) connections

Description : Consider the following statements regarding three-phase transformers in Open -Delta (V -V) connections :  1. Being a temporary remedy when one transformer forms of Delta -Delta system is &imaged, and removed from service.  ... and 2 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3

Last Answer : Consider the following statements regarding three-phase transformers in Open -Delta (V -V) connections :  1. Being a temporary remedy when one transformer forms of Delta -Delta system is &imaged, and removed from service.  ... and 2 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3

When troubleshooting a console circuit card which is suspected of being faulty, the first step would be to _____. A. pull the card and measure the value of all resistors B. check for the correct value and polarity of all power connections to the card C. de-energize and pull the card to visually inspect for burned components D. check for continuity of circuit board traces and then the gain of each transistor

Description : When troubleshooting a console circuit card which is suspected of being faulty, the first step would be to _____. A. pull the card and measure the value of all resistors B. check for the ... for burned components D. check for continuity of circuit board traces and then the gain of each transistor

Last Answer : Answer: C

Which of the following is a characteristic of fractional horsepower repulsion start motors? A. They start with a rotating stator field. B. The short circuiting ring is removed from the commutator while starting. C. The brushes are removed from the commutator while starting. D. They have a low starting torque.

Description : Which of the following is a characteristic of fractional horsepower repulsion start motors? A. They start with a rotating stator field. B. The short circuiting ring is removed from the commutator while ... brushes are removed from the commutator while starting. D. They have a low starting torque.

Last Answer : Answer: B

In the maintenance phase the product must be tested against previous test cases. This is known as testing. (a) Unit (b) Integration (c)Regression (d) Module (e) Beta

Description : In the maintenance phase the product must be tested against  previous test cases. This is known as testing. (a) Unit (b) Integration (c)Regression (d) Module (e) Beta

Last Answer : (c)Regression

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

A CT has 2 – secondary windings. If we use only one secondary winding can we keep the unused secondary winding short circuited?

Description : A CT has 2 – secondary windings. If we use only one secondary winding can we keep the unused secondary winding short circuited?

Last Answer : No. If it is short-circuited then the ratio will not get correctly. The turns of primary winding will be shared between 2 secondary windings. So the unused secondary winding should kept open. 

Which statement is true concerning a split-phase induction motor? A. Motor rotation can be reversed without changing the windings or leads. B. Motor speed can be readily adjusted from zero to full speed. C. The motor will run as a generator with the proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

Description : Which statement is true concerning a split-phase induction motor? A. Motor rotation can be reversed without changing the windings or leads. B. Motor speed can be readily adjusted from zero to full ... proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

Last Answer : Answer: D

When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter pointer _____________. A. fluctuating around a constant resistance reading B. dipping towards 'zero', then rising slowly C. kicking slightly downscale as voltage is applied D. continually rising as the test voltage is applied

Description : When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter pointer _____________. A. fluctuating around a ... slightly downscale as voltage is applied D. continually rising as the test voltage is applied

Last Answer : Answer: C