Which of the following statements represents the important factor that must be considered when replacing a faulty diode in the exciter rectifier assembly? A. Be certain that the replacement diode is the same polarity as the one removed. B. Never alter the diode alignment to cause a change in the neutral plane. C. Replacement of a diode also requires balancing of the rotor with a one-piece rotor lamination to be shrunk fit and keyed to the shaft. D. The replacement diode must be dipped in varnish prior to installation to protect against humidity.

Which of the following statements represents the important factor that must be considered when replacing a faulty diode in the exciter rectifier assembly? A. Be certain that the replacement diode is the same polarity as the one removed. B. Never alter the diode alignment to cause a change in the neutral plane. C. Replacement of a diode also requires balancing of the rotor with a one-piece rotor lamination to be shrunk fit and keyed to the shaft. D. The replacement diode must be dipped in varnish prior to installation to protect against humidity.
by

1 Answer

Answer :

Answer: A
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Related questions

When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its base B. there is a danger of phosphor poisoning should 'B''s bulb break C. component 'D' must be closed during the replacement to provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Description : When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Last Answer : Answer: D

Will rotor earth fault relay operate for earth fault in main exciter winding or RCU Diode Bridge also?

Description : Will rotor earth fault relay operate for earth fault in main exciter winding or RCU Diode Bridge also? 

Last Answer : Yes. 

To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. stowed upright on its shaft C. supported by two 'V' notched wood blocks D. returned to the frame as soon as the bearings are removed

Description : To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. stowed upright on its shaft C. supported by two 'V' notched wood blocks D. returned to the frame as soon as the bearings are removed

Last Answer : Answer: C

Unnecessary and frequent applications of varnish to the generator windings to repair defective insulation will result in ____________. A. heavy coatings of varnish interfering with heat dissipation B. deficient air gap clearance and eventual damage to the casing C. failure of the rectifier assembly D. a built-up of varnish without changing generator operation

Description : Unnecessary and frequent applications of varnish to the generator windings to repair defective insulation will result in ____________. A. heavy coatings of varnish interfering with heat dissipation B. ... of the rectifier assembly D. a built-up of varnish without changing generator operation

Last Answer : Answer: A

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

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

If an AC generator experiences voltage failure, the cause may be _____________. A. an open in the field circuit B. the brushes shifting out of the neutral plane C. excessive locked-rotor current D. a rotating slip ring

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Last Answer : Answer: A

In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded for 10 minutes to remove static charges. B. The transformer connections must be made as before with regard to the indicated polarity. C. The iron core of the transformer must be flashed to pre-magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Description : In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded ... magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Last Answer : Answer: B

When changing out component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its base B. there is a danger of phosphor poisoning should 'B''s bulb break C. component 'D' must be closed during the replacement to provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Description : When changing out component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Last Answer : Answer: D

Prior to taking a resistance reading with a volt-ohm-milliammeter, the 'zero' setting must be adjusted. After clipping the two leads together, you find the adjustment knob will not return the pointer to 'zero'. This is most likely an indication of ______ A. an improper resistance range setting B. weak batteries C. a faulty zero ohms knob D. a faulty meter movement

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Last Answer : Answer: B

Figure 'C' shown in the illustration represents a _________. EL-0078 A. silicon controlled rectifier B. light emitting diode C. photosensitive diode D. Zener diode

Description : Figure 'C' shown in the illustration represents a _________. EL-0078 A. silicon controlled rectifier B. light emitting diode C. photosensitive diode D. Zener diode

Last Answer : Answer: C

Figure 'D' shown in the illustration represents a _________. EL-0067 A. silicon controlled rectifier B. light emitting diode C. photosensitive diode D. Zener diode

Description : Figure 'D' shown in the illustration represents a _________. EL-0067 A. silicon controlled rectifier B. light emitting diode C. photosensitive diode D. Zener diode

Last Answer : Answer: B

In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. squirrel cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor

Description : In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. ... cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor

Last Answer : Answer: C

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Description : What can be used to replace the exciter in the circuit shown in the illustration? EL-0101 A. A step-up transformer. B. A rectifier. C. A step-down transformer. D. An operational amplifier.

Last Answer : Answer: B

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 listed conditions could cause a DC motor to have excessively hot windings and sparking at the brushes? A. Reversed interpole polarity B. High bar-to-bar voltage C. Loose brushes D. Excessive humidity

Description : Which of the listed conditions could cause a DC motor to have excessively hot windings and sparking at the brushes? A. Reversed interpole polarity B. High bar-to-bar voltage C. Loose brushes D. Excessive humidity

Last Answer : Answer: A

A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an _____________. A. rotor B. stator C. exciter D. armature

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Last Answer : Answer: C

Which of the following components are used to convert alternating current produced in the generator windings to direct current? A. Armature and equalizer B. Commutator and brushes C. Rotor and interpoles D. Field and exciter

Description : Which of the following components are used to convert alternating current produced in the generator windings to direct current? A. Armature and equalizer B. Commutator and brushes C. Rotor and interpoles D. Field and exciter

Last Answer : Answer: B

To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. wrapped in several layers of heavy paper or cardboard C. supported by flat wood blocks on the workbench D. returned to the frame as soon as the bearings are removed

Description : To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. wrapped in several layers of heavy ... flat wood blocks on the workbench D. returned to the frame as soon as the bearings are removed

Last Answer : Answer: B

The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. changing the RPM of the rotor flux C. changing the phase sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

Description : The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

Last Answer : Answer: A

The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. separate exciter in a series with the shunt field C. carbon pile regulator in series with the load D. balance coil diverting neutral current through the shunt field

Description : The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. ... in series with the load D. balance coil diverting neutral current through the shunt field

Last Answer : Answer: A

A split-phase induction squirrel-cage motor will not come up to speed, even though the rated voltage, rated frequency, and rated load are applied. The suspected trouble could be due to _____________. A. a faulty centrifugal switch B. broken rotor bars C. worn bearings D. all of the above

Description : A split-phase induction squirrel-cage motor will not come up to speed, even though the rated voltage, rated frequency, and rated load are applied. The suspected trouble could be due to _____________. A. a faulty centrifugal switch B. broken rotor bars C. worn bearings D. all of the above

Last Answer : Answer: D

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Last Answer : Answer: D

In the illustration, the diode between terminals 16 and 17 is to _________. EL-0046 A. insure that the voltage across the governor coil (EG-3P) never exceeds .6 VDC B. compensate for the temperature difference of the governor oil heating up C. protect the electronic governor from counter EMF D. act as a filter to prevent hunting

Description : In the illustration, the diode between terminals 16 and 17 is to _________. EL-0046 A. insure that the voltage across the governor coil (EG-3P) never exceeds .6 VDC B. compensate for the ... heating up C. protect the electronic governor from counter EMF D. act as a filter to prevent hunting

Last Answer : Answer: C

Which of the following statements represents the FIRST precaution to be taken prior to working on any installed electrical component? A. Wear rubber gloves and boots. B. Use only approved nonconducting tools. C. Ground the case of the machine before beginning any repairs. D. Open the supply circuits and tag the switches.

Description : Which of the following statements represents the FIRST precaution to be taken prior to working on any installed electrical component? A. Wear rubber gloves and boots. B. Use only approved nonconducting ... the machine before beginning any repairs. D. Open the supply circuits and tag the switches.

Last Answer : Answer: D

Which of the following statements represents the correct method of connecting the shunt of an ammeter prior to taking a reading? A. In series with the load and in series with the meter movement. B. In series with the load and in parallel with the meter movement. C. In parallel with the load and in series with the meter movement. D. In parallel with the load and in parallel with the meter movement.

Description : Which of the following statements represents the correct method of connecting the shunt of an ammeter prior to taking a reading? A. In series with the load and in series with the meter movement. B. In ... with the meter movement. D. In parallel with the load and in parallel with the meter movement.

Last Answer : Answer: B

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

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Before a diode will conduct, the cathode must be what polarity relative

Description : Before a diode will conduct, the cathode must be what polarity relative

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Which of the following statements regarding the use of a current measuring instrument is correct? A. It must be connected in series with the circuit. B. You should always start with the lowest range until a suitable reading is obtained. C. The indicating needle is deflected from left to right regardless of polarity. D. An external shunt is generally utilized where current is less than 10 amperes.

Description : Which of the following statements regarding the use of a current measuring instrument is correct? A. It must be connected in series with the circuit. B. You should always start with the lowest range ... of polarity. D. An external shunt is generally utilized where current is less than 10 amperes.

Last Answer : Answer: A

On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock B. create an isolated ground for the instrumentation C. allow for the expansion of the generator away from the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Description : On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock ... the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Last Answer : Answer: D

Which of the following statements is/are true? A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction B. Shaft vibrates with maximum frequency when rotors rotate in same direction C. Zero node behavior is observed in rotors rotating in opposite direction D. All of the above

Description : Which of the following statements is/are true? A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction B. Shaft vibrates with maximum frequency when rotors ... C. Zero node behavior is observed in rotors rotating in opposite direction D. All of the above

Last Answer : A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction

Which of the following statements is/are true? A) Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction B) Shaft vibrates with maximum frequency when rotors rotate in same direction C) Zero node behavior is observed in rotors rotating in opposite direction D) All of the above

Description : Which of the following statements is/are true? A) Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction B) Shaft vibrates with maximum frequency when rotors ... C) Zero node behavior is observed in rotors rotating in opposite direction D) All of the above

Last Answer : A) Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction

Which of the following statements is/are true? a. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction b. Shaft vibrates with maximum frequency when rotors rotate in same direction c. Zero node behavior is observed in rotors rotating in opposite direction d. All of the above

Description : Which of the following statements is/are true? a. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction b. Shaft vibrates with maximum frequency when rotors ... c. Zero node behavior is observed in rotors rotating in opposite direction d. All of the above

Last Answer : a. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction

In an alternating current electrical system, a low system power factor is a direct sign of _____________. A. wasted energy B. efficient operation C. a short in the exciter field windings D. an excessive number of minor system grounds

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Last Answer : Answer: A

If a synchronous motor begins to vibrate severely and pull out of synchronism, the cause may be ____________. A. an overload B. an open in the field coils C. no exciter voltage D. all of the above

Description : If a synchronous motor begins to vibrate severely and pull out of synchronism, the cause may be ____________. A. an overload B. an open in the field coils C. no exciter voltage D. all of the above

Last Answer : Answer: D

Brushes in a generator must be positioned in the neutral plane to avoid sparking between the brushes and the _____________. A. yoke B. armature windings C. field pole windings D. commutator

Description : Brushes in a generator must be positioned in the neutral plane to avoid sparking between the brushes and the _____________. A. yoke B. armature windings C. field pole windings D. commutator

Last Answer : Answer: D

One diode of a full-wave rectifier has burned out in a shorted condition. Therefore, the output will be ____________. A. zero B. a rectified half-wave C. a rectified full-wave D. equal to the AC input

Description : One diode of a full-wave rectifier has burned out in a shorted condition. Therefore, the output will be ____________. A. zero B. a rectified half-wave C. a rectified full-wave D. equal to the AC input

Last Answer : Answer: D

A full-wave rectifier has one diode burned out in an open condition, what will be the output characteristic of the device? A. Zero B. Half-wave rectified C. Full-wave rectified D. Equal to the AC input

Description : A full-wave rectifier has one diode burned out in an open condition, what will be the output characteristic of the device? A. Zero B. Half-wave rectified C. Full-wave rectified D. Equal to the AC input

Last Answer : Answer: B

What are the advantages of free wheeling diode in rectifier circuit?

Description : What are the advantages of free wheeling diode in rectifier circuit?

Last Answer : The input power factor is improved. It prevents the output voltage from becoming negative. Load current waveform is improved.

Define given parameters and state their values for bridge rectifier (i) Ripple factor (ii) PIV of diode.

Description : Define given parameters and state their values for bridge rectifier (i) Ripple factor (ii) PIV of diode.

Last Answer : Ripple Factor: Ripple Factor is defined as the ratio of RMS value of the AC component of output to the DC or average value of the output. Mathematically it is expressed as, ( ... which appears across non-conducting reverse biased diode. (ii) PIV of diode for bridge rectifier-Vm

Name the type of rectifier for each of following feature : (i) Highest rectifier efficiency (ii) Highest form factor (iii) Two diode rectifier circuit (iv) PIV = 2Vm.

Description : Name the type of rectifier for each of following feature : (i) Highest rectifier efficiency (ii) Highest form factor (iii) Two diode rectifier circuit (iv) PIV = 2Vm.

Last Answer : (i) Highest rectifier efficiency : Center tapped & Bridge full wave Rectifier  (ii) Highest form factor : Center tapped & Bridge full wave Rectifier  (iii) Two diode rectifier circuit : Center tapped full wave Rectifier  (iv) PIV = 2Vm : Center tapped full wave Rectifier

Agonists affect the receptor molecule in the following manner: A. Alter its amino acid sequence B. Denature the receptor protein C. Alter its folding or alignment of subunits D. Induce covalent bond formation

Description : Agonists affect the receptor molecule in the following manner: A. Alter its amino acid sequence B. Denature the receptor protein C. Alter its folding or alignment of subunits D. Induce covalent bond formation

Last Answer : C. Alter its folding or alignment of subunits

Agonists affect the receptor molecule in the following manner: A. Alter its amino acid sequence B. Denature the receptor protein C. Alter its folding or alignment of subunits D. Induce covalent bond formation

Description : Agonists affect the receptor molecule in the following manner: A. Alter its amino acid sequence B. Denature the receptor protein C. Alter its folding or alignment of subunits D. Induce covalent bond formation

Last Answer : C. Alter its folding or alignment of subunits

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Description : Keyed joints never lead to stress concentration on shafts. a) True b) False

Last Answer : b) False

The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the bearings C. strictly converted to heat generated by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work

Description : The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the ... by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work

Last Answer : Answer: A

The torque produced by a motor when its shaft will not turn, even though rated voltage is applied to the stator, is known as _____________. A. locked-rotor torque B. pullout torque C. breakdown torque D. torque margin

Description : The torque produced by a motor when its shaft will not turn, even though rated voltage is applied to the stator, is known as _____________. A. locked-rotor torque B. pullout torque C. breakdown torque D. torque margin

Last Answer : Answer: A

What are the effects of broken rotor bars and broken shaft parts?

Description : What are the effects of broken rotor bars and broken shaft parts?

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