Will The Alternators Have Rotating Armature System Or Stationary Armature System?

Will The Alternators Have Rotating Armature System Or Stationary Armature System?
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1 Answer

Answer :

Generally in alternators, the armature is stationary and the field rotates. Small low-voltage alternators often have a rotating armature and a stationary field winding. But in large alternators rotating armature field type is used.
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Related questions

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

What Are The Advantages Of Stationary Armature And Rotating Field System?

Description : What Are The Advantages Of Stationary Armature And Rotating Field System?

Last Answer : The stationary armature coils can be insulated easily. Higher peripheral speed can be achieved in the rotor. Cooling of the winding is more efficient. Only two slip rings are required to give DC ... Output current can be easily supplied to the load circuit. Slip-rings and brushes are not necessary.

The most common type of AC service generator found aboard ship is the stationary _____________. A. electromagnetic field, revolving armature type B. electromagnetic field, oscillatory armature type C. armature, oscillatory electromagnet field type D. armature, rotating electromagnetic field type

Description : The most common type of AC service generator found aboard ship is the stationary _____________. A. electromagnetic field, revolving armature type B. electromagnetic field, oscillatory armature type C. armature, oscillatory electromagnet field type D. armature, rotating electromagnetic field type

Last Answer : Answer: D

An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a ____________. A. magnetic amplifier B. ship's service alternator C. three-wire DC generator D. saturable core reactor

Description : An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a ____________. A. magnetic amplifier B. ship's service alternator C. three-wire DC generator D. saturable core reactor

Last Answer : Answer: B

In a d.c. machine, the armature mmf is (A) stationary w.r.t. armature. (B) rotating w.r.t. field. (C) stationary w.r.t. field. (D) rotating w.r.t. brushes.

Description : In a d.c. machine, the armature mmf is (A) stationary w.r.t. armature. (B) rotating w.r.t. field. (C) stationary w.r.t. field. (D) rotating w.r.t. brushes.

Last Answer : (C) stationary w.r.t. field.

If the pointer of the synchroscope is rotating in the slow direction when you are preparing to parallel two alternators, the _____________. A. incoming machine is turning faster than the load alternator B. loaded alternator is turning faster than the incoming machine C. load on the loaded alternator is ready to split D. incoming machine is beginning to pick up some of the load

Description : If the pointer of the synchroscope is rotating in the slow direction when you are preparing to parallel two alternators, the _____________. A. incoming machine is turning faster than the load alternator B ... alternator is ready to split D. incoming machine is beginning to pick up some of the load

Last Answer : Answer: B

What is meant by armature reaction in Alternators?

Description : What is meant by armature reaction in Alternators?

Last Answer : The effect of armature flux on main flux

In an induction motor, rotor currents are circulated in the rotor by _____________. A. slip rings and brushes B. an armature and brushes C. inductive reaction of the rotating stator field D. external variable resistors

Description : In an induction motor, rotor currents are circulated in the rotor by _____________. A. slip rings and brushes B. an armature and brushes C. inductive reaction of the rotating stator field D. external variable resistors

Last Answer : Answer: C

State advantages of rotating field type alternators.

Description : State advantages of rotating field type alternators. 

Last Answer : Advantages of Rotating Field Type Alternator: 1) For high-voltage alternator, large space is required to accommodate conductors with insulation, as high voltage is induced in them. If field poles are placed ... is kept rotating. 8) Rotating field is comparatively light and can run with high speed. 

In single-phase alternators, in order for the voltages induced in all the armature windings to add together for a single output, how must the windings be connected?

Description : In single-phase alternators, in order for the voltages induced in all the armature windings to add together for a single output, how must the windings be connected?

Last Answer : In series.

The angular displacement between two interconnected stations is mainly due to (a) armature reactance of both alternators (b) reactance of the interconnector (c) synchronous reactance of both the alternators (d) all of the above

Description : The angular displacement between two interconnected stations is mainly due to (a) armature reactance of both alternators (b) reactance of the interconnector (c) synchronous reactance of both the alternators (d) all of the above

Last Answer : (a) armature reactance of both alternators

Two 3-phase, Y-connected alternators are to be paralleled to a set of common busbars. The armature has a

Description : Two 3-phase, Y-connected alternators are to be paralleled to a set of common busbars. The armature has a per phase synchronous reactance of 1.7 Ohm and negligible armature resistance. The line voltage of the first machine is adjusted to ... will be  (A) 16.98 A (B) 29.41 A (C) 33.96 A (D) 58.82 A

Last Answer : Two 3-phase, Y-connected alternators are to be paralleled to a set of common busbars. The armature has a per phase synchronous reactance of 1.7 Ohm and negligible armature resistance. The ... instant they are paralleled. Under this condition, the synchronizing current per phase will be 16.98 A

Does this microwave have a rotating plate inside or is it stationary?

Description : Does this microwave have a rotating plate inside or is it stationary?

Last Answer : This microwave has a 12 5/8 in. rotating turntable inside.

The static load is defined as the load acting on the bearing when the shaft is _____. (a) stationary (b) rotating at rpm<5 (c) rotating at rpm<10 (d) rotating at rpm<15

Description : The static load is defined as the load acting on the bearing when the shaft is _____. (a) stationary (b) rotating at rpm

Last Answer : (a) stationary

Static load is defined as the load acting on the bearing when shaft is _____ a) Stationary b) Rotating at rpm<10 c) Rotating at rpm<5 d) None of the listed

Description : Static load is defined as the load acting on the bearing when shaft is _____ a) Stationary b) Rotating at rpm

Last Answer : a) Stationary

Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) None of the listed

Description : Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) None of the listed

Last Answer : c) Moving or stationary

Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) None of the listed

Description : Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) None of the listed

Last Answer : c) Moving or stationary

Is the field rotating or stationary?

Description : Is the field rotating or stationary?

Last Answer : Rotating. To confirm check Dennis T Hall.

Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) fixed

Description : Is it necessary for an axle to be ______ with respect to rotating element? a) Stationary b) Moving c) Moving or stationary d) fixed

Last Answer : c) Moving or stationary

The graph shown in the illustration represents the speed droop curves of two equal capacity alternators about to be paralleled. When paralleled, the greater portion of the total load above 60% for each unit will be picked up _____________. EL-0025 A. by unit 'A' B. by unit 'B' C. equally by each unit D. none of the above

Description : The graph shown in the illustration represents the speed droop curves of two equal capacity alternators about to be paralleled. When paralleled, the greater portion of the total load above 60% for each unit will be picked up ... unit 'A' B. by unit 'B' C. equally by each unit D. none of the above

Last Answer : Answer: A

The load sharing characteristics of two diesel alternators operating in parallel are directly related to the setting of their governors' ____________. A. load limit B. idle speed C. speed limit D. speed droop

Description : The load sharing characteristics of two diesel alternators operating in parallel are directly related to the setting of their governors' ____________. A. load limit B. idle speed C. speed limit D. speed droop

Last Answer : Answer: D

Which of the following statements is true concerning the operation of two alternators in parallel? A. The cycles per second of each alternator are the same. B. Both alternator governors must be set with the same amount of speed droop. C. The number of field poles must be the same on each alternator. D. The load must always be divided equally between alternators.

Description : Which of the following statements is true concerning the operation of two alternators in parallel? A. The cycles per second of each alternator are the same. B. Both alternator governors must be set ... be the same on each alternator. D. The load must always be divided equally between alternators.

Last Answer : Answer: A

Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling? A. The rotor of the loaded alternator will hunt. B. Severe cross currents will occur which could cause damage. C. The rotor of the incoming alternator will stop. D. Both alternators will parallel 180° out of phase.

Description : Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling? A. The rotor of the ... The rotor of the incoming alternator will stop. D. Both alternators will parallel 180° out of phase.

Last Answer : Answer: B

Equalization of the power factors of two alternators operating in parallel is accomplished _____________. A. manually, by adjusting the governor controls B. automatically, by automatic voltage regulators C. manually, adjusting the output of current transformers D. automatically, by the designed action of the governors

Description : Equalization of the power factors of two alternators operating in parallel is accomplished _____________. A. manually, by adjusting the governor controls B. automatically, by automatic voltage regulators ... the output of current transformers D. automatically, by the designed action of the governors

Last Answer : Answer: B

After closing the circuit breaker to place two similar alternators in parallel, the NEXT step is to balance the _____________. A. power factor B. voltage load C. kilowatt load D. ampere load

Description : After closing the circuit breaker to place two similar alternators in parallel, the NEXT step is to balance the _____________. A. power factor B. voltage load C. kilowatt load D. ampere load

Last Answer : Answer: C

Two paralleled alternators are operating near rated load. If one trips out mechanically, which of the listed actions should be taken FIRST? A. Restart the tripped machine immediately. B. Strip the board of all non-vital circuits. C. Start the emergency generator. D. Transfer all vital loads to the emergency bus.

Description : Two paralleled alternators are operating near rated load. If one trips out mechanically, which of the listed actions should be taken FIRST? A. Restart the tripped machine immediately. B. Strip the board ... circuits. C. Start the emergency generator. D. Transfer all vital loads to the emergency bus.

Last Answer : Answer: B

Why is it a good practice to have the frequency of the incoming alternator adjusted slightly higher than that of the loaded alternator when paralleling two alternators? A. This allows the oncoming machine to accept load immediately. B. This prevents the machine from floating on the line. C. The reverse power relay is prevented from activating. D. All of the above.

Description : Why is it a good practice to have the frequency of the incoming alternator adjusted slightly higher than that of the loaded alternator when paralleling two alternators? A. This allows the oncoming machine to ... line. C. The reverse power relay is prevented from activating. D. All of the above.

Last Answer : Answer: D

The KW load is evenly distributed between two alternators just placed in parallel by adjusting _____________. A. a balance coil B. the governor settings C. the field excitation D. a rheostat

Description : The KW load is evenly distributed between two alternators just placed in parallel by adjusting _____________. A. a balance coil B. the governor settings C. the field excitation D. a rheostat

Last Answer : Answer: B

When paralleling two alternators, the synchronizing lamps remain lit as the synchroscope pointer approaches the 0°. This indicates the _____________. A. incoming alternator is running too fast B. alternator voltages are 180 degrees apart C. synchroscope is defective or broken D. alternator power factors are in phase

Description : When paralleling two alternators, the synchronizing lamps remain lit as the synchroscope pointer approaches the 0°. This indicates the _____________. A. incoming alternator is running too fast B. alternator ... apart C. synchroscope is defective or broken D. alternator power factors are in phase

Last Answer : Answer: C

When paralleling two alternators the synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates the ____________. A. alternator voltages are 180° apart B. incoming alternator is running too fast C. incoming alternator is in phase with the bus voltage D. synchroscope pointer is defective or broken

Description : When paralleling two alternators the synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates the ____________. A. alternator voltages ... alternator is in phase with the bus voltage D. synchroscope pointer is defective or broken

Last Answer : Answer: C

When paralleling two alternators using three synchronizing lamps, the flickering of all three lamps becomes progressively slower and slower. This means the ______________. A. frequency of the incoming generator is approaching that of the bus B. frequency of the incoming alternator is less than that of the bus C. phase rotation of the incoming alternators is opposite to that of the bus D. terminal voltage of the incoming alternator is approaching that of the bus

Description : When paralleling two alternators using three synchronizing lamps, the flickering of all three lamps becomes progressively slower and slower. This means the ______________. A. frequency of the incoming ... the bus D. terminal voltage of the incoming alternator is approaching that of the bus

Last Answer : Answer: A

You are paralleling two alternators. The synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates that the ____________. A. alternator voltages are 180° apart B. circuit breaker can be closed C. incoming alternator is running too slowly D. synchroscope is defective or broken

Description : You are paralleling two alternators. The synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates that the ____________. A. alternator ... be closed C. incoming alternator is running too slowly D. synchroscope is defective or broken

Last Answer : Answer: B

If the excitation is increased to one of two alternators operating in parallel, the _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. kilowatt load will be greatly increased D. ampere load will be greatly decreased

Description : If the excitation is increased to one of two alternators operating in parallel, the _____________. A. power factor will change in the lagging direction B. power factor will change in the leading direction C. kilowatt load will be greatly increased D. ampere load will be greatly decreased

Last Answer : Answer: A

To equalize the power factor of two alternators operating in parallel, the ____________. A. field excitation of both units is adjusted B. governors of both units are adjusted C. phase sequence is altered D. kilowatt load is evenly divided

Description : To equalize the power factor of two alternators operating in parallel, the ____________. A. field excitation of both units is adjusted B. governors of both units are adjusted C. phase sequence is altered D. kilowatt load is evenly divided

Last Answer : Answer: A

Which of the following devices are protected from being motorized by a reversepower relay? A. Alternators B. Wave guides C. Exciters D. Amplidynes

Description : Which of the following devices are protected from being motorized by a reversepower relay? A. Alternators B. Wave guides C. Exciters D. Amplidynes

Last Answer : Answer: A

The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation of the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. type of alternator

Description : The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation of the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. type of alternator

Last Answer : Answer: B

The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation to the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. number of field poles per alternator

Description : The division of kilowatt load between two paralleled alternators is determined by the _____________. A. amount of field excitation to the leading machine B. load-speed characteristics of the governors C. amount of field excitation to the lagging machine D. number of field poles per alternator

Last Answer : Answer: B

Handheld phase sequence indicators are useful when ________. A. preparing to parallel alternators B. connecting lighting branch circuits C. troubleshooting DC motors D. connecting shore power lines to the ship

Description : Handheld phase sequence indicators are useful when ________. A. preparing to parallel alternators B. connecting lighting branch circuits C. troubleshooting DC motors D. connecting shore power lines to the ship

Last Answer : Answer: D

What Are The Various Types Of Rotors Used In The Alternators?

Description : What Are The Various Types Of Rotors Used In The Alternators?

Last Answer : Salient pole rotor Non- salient pole rotor and Cylindrical rotor

What Is Meant By Turbo Alternators?

Description : What Is Meant By Turbo Alternators?

Last Answer : Turbo alternators are high speed alternators. Because of high speed of rotation, the rotor diameter is reduced and the axial length is increased. Two or four poles are generally used and steam turbines are used as prime movers.

What Is Basic Principle Of Operation Of Alternators/dc Generators?

Description : What Is Basic Principle Of Operation Of Alternators/dc Generators?

Last Answer : They are working on the fundamental principle based on Faraday’s Laws of Electromagnetic Induction. This law states that, When a current carrying conductor moves in magnetic field, it induces an EMF.

How synchronoscope is used for synchronizing Alternators?

Description : How synchronoscope is used for synchronizing Alternators?

Last Answer : Synchronoscope can be used for permanently connected Alternators where the correctness of phase sequence is already checked by other means. The rotation of pointer is proportional to the difference in ... alternator is running slow. If the difference in frequency is large the pointer will oscillate

State the condition to be satisfied before connecting two alternators in parallel

Description : State the condition to be satisfied before connecting two alternators in parallel

Last Answer : The following are the three conditions to be satisfied by synchronizing the additional Alternator with the existing one or the common bus-bars. · The terminal voltage magnitude of the incoming ... incoming Alternator voltage must be the same as the bus-bar voltage. . Zero phase difference

What is need of parallel operation of alternators?

Description : What is need of parallel operation of alternators?

Last Answer : 1. Optimum utilization of alternators as most of the power stations are interconnected by grid. 2. Reduced operating cost: number of alternators operating at a time can be changed depending on ... demands. 3. Easy maintenance: Alternator may be shut down for maintenance 4. Continuity and reliability

What are the causes of changes in voltage in Alternators when loaded?

Description : What are the causes of changes in voltage in Alternators when loaded?

Last Answer : When alternator is loaded the armature carries load current. Due to this load current the voltage drops occur in alternator. Hence terminal voltage decreases due to following voltage drops: 1. Voltage ... the leakage reactance of the winding, Xl 3· Voltage drop due to the armature reactance, Xa

Why alternators are rated in KVA?

Description : Why alternators are rated in KVA?

Last Answer : The KVA rating of ac machine depends on the power factor of the load. The power factor in turn depends on the operating conditions. The operating conditions differ from place to place. Therefore the KVA rating is specified for all ac machines.

Why are Alternators rated in kVA and not in kW?

Description : Why are Alternators rated in kVA and not in kW?

Last Answer : The continuous power rating of any machine is generally defined as the power the machine or apparatus can deliver for a continuous period so that the losses incurred in the machine gives rise to a ... generator , the Alternators have only their apparent power in VA/kVA/MVA as their power rating.

Why do cylindrical Alternators operate with steam turbines?

Description : Why do cylindrical Alternators operate with steam turbines?

Last Answer : A: Steam turbines are found to operate at fairly good efficiency only at high speeds. The high speed operation of rotors tends to increase mechanical losses and so the rotors should have a ... axial length are used for Synchronous generators driven by steam turbines with either 2 or 4 poles.

How are alternators classified?

Description : How are alternators classified?

Last Answer : According to shape of field system · Salient pole type · Smooth cylindrical type