In a salient pole synchronous machine (usual symbols are used): (A) xq > xd (B) xq = xd (C) xq < xd (D) 0

In a salient pole synchronous machine (usual symbols are used):
(A) xq > xd (B) xq = xd
(C) xq < xd (D) 0
by

1 Answer

Answer :

Ans: C
Since reluctance on the q axis is higher, owing to the larger air gap, hence xq < xd
by

Related questions

Slip test is performed to determine : (A) Slip in an induction motor vtkgi Xd and Xq in a salient pole alternator

Description : Slip test is performed to determine :  (A) Slip in an induction motor  (B) Xd and Xq in a salient pole alternator  (C) Synchronous impedance in an alternator  (D) Positive and negative sequence impedances of an alternator

Last Answer : Slip test is performed to determine :  Xd and Xq in a salient pole alternator 

The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)

Description : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

Last Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only

What are the advantages of salient pole type of construction used for synchronous machines?

Description : What are the advantages of salient pole type of construction used for synchronous machines?

Last Answer : 1. They allow better ventilation. 2 The pole faces are so shaped radial air gap length increases from the pole center to the pole tips so that flux distribution in the air gap is ... 3 Due the variable reluctance, the machine develops additional reluctance power, which is independent of excitation.

If the field circuits of an unloaded salient pole synchronous motor gets suddenly open circuited, then (A) The motor stops. (B) It continues to run at the same speed. (C) Its runs at the slower speed. (D) It runs at a very high speed.

Description : If the field circuits of an unloaded salient pole synchronous motor gets suddenly open circuited, then (A) The motor stops. (B) It continues to run at the same speed. (C) Its runs at the slower speed. (D) It runs at a very high speed.

Last Answer : Ans: B The motor continues to run at the same speed because synchronous motor speed does not depend upon load, Nα f.

A salient pole synchronous motor is running at no load. Its field current is switched off. The motor will (A) come to stop. (B) continue to run at synchronous speed. (C) continue to run at a speed slightly more than the synchronous speed. (D) continue to run at a speed slightly less than the synchronous speed.

Description : A salient pole synchronous motor is running at no load. Its field current is switched off. The motor will (A) come to stop. (B) continue to run at synchronous speed. (C) continue to run at ... more than the synchronous speed. (D) continue to run at a speed slightly less than the synchronous speed.

Last Answer : (B) continue to run at synchronous speed.

The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and

Description : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is (A) 0.25 pu (B) 0.5 pu (C) 1.0 pu (D) 1.5 pu

Last Answer : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is 0.5 pu

The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu

Description : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are (A) 0.5 pu ... pu, 0.5 pu (C) 0.707 pu, 0.707 pu (D) 0.5 pu, 0.5 pu

Last Answer : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are 0.866 pu, 0.5 pu

A three phase, salient pole synchronous motor is connected to an infinite bus. It is operated at no load a

Description : A three phase, salient pole synchronous motor is connected to an infinite bus. It is operated at no load a normal excitation. The field excitation of the motor is first reduced to zero ... First increases and then decreases steeply (C) First decreases and then increases steeply (D) Remains constant

Last Answer : B

If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will?

Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.

what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?

Description : what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?

Last Answer : When excitation of an unloaded salient pole synchronous motor suddenly gets disconnected the motor will stop.

Which of the following types of DC motors has its field connected in parallel with its armature? A. Counter EMF B. Shunt C. Salient pole D. Series

Description : Which of the following types of DC motors has its field connected in parallel with its armature? A. Counter EMF B. Shunt C. Salient pole D. Series

Last Answer : Answer: B

What type of rotor is used in split-phase motors? A. Drum B. Salient pole C. Squirrel-cage D. Wound-rotor

Description : What type of rotor is used in split-phase motors? A. Drum B. Salient pole C. Squirrel-cage D. Wound-rotor

Last Answer : Answer: C

What are the prime movers used for a) Salient pole alternator, b) Non- salient pole alternator.

Description : What are the prime movers used for a) Salient pole alternator, b) Non- salient pole alternator.

Last Answer : The prime movers used for salient pole alternators are water wheels likeKaplan turbine, Francis turbine, Pelton wheel etc., and diesel or petrol engines. The prime movers used for non-salient pole alternators are steam turbines and gas turbines.

A synchronous motor starts as usual but fails to develop its full torque. What could it be due to?

Description : A synchronous motor starts as usual but fails to develop its full torque. What could it be due to?

Last Answer : a. Exciter voltage may be too low. b. Field spool may be reversed c. There may be either open-circuit or short-circuit in the field.

A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3

Description : A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3

Last Answer : Answer: A

A four-pole 60-hertz induction motor has a synchronous speed of 1800 RPM and a slip of 4 percent at full load. What will be its full load speed? A. 1728.0 RPM B. 1730.7 RPM C. 1800.0 RPM D. 1872.0 RPM

Description : A four-pole 60-hertz induction motor has a synchronous speed of 1800 RPM and a slip of 4 percent at full load. What will be its full load speed? A. 1728.0 RPM B. 1730.7 RPM C. 1800.0 RPM D. 1872.0 RPM

Last Answer : Answer: A

Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency? A. A four-pole synchronous motor under normal load. B. A four-pole induction motor under no load. C. A six-pole synchronous motor under normal load. D. A six-pole induction motor under full load.

Description : Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency? A. A four-pole synchronous motor under normal load. B. A four-pole induction motor under ... A six-pole synchronous motor under normal load. D. A six-pole induction motor under full load.

Last Answer : Answer: A

If the synchronous speed of a 12 pole, polyphase, induction motor operating at 60 Hz were 600 RPM, how many poles will be required in a similar motor operating at the same frequency but having a synchronous speed of 900 RPM? A. 4 B. 6 C. 8 D. 18

Description : If the synchronous speed of a 12 pole, polyphase, induction motor operating at 60 Hz were 600 RPM, how many poles will be required in a similar motor operating at the same frequency but having a synchronous speed of 900 RPM? A. 4 B. 6 C. 8 D. 18

Last Answer : Answer: C

A shaded-pole motor is a ____________. A. synchronous motor B. three-phase induction motor C. compound-wound motor D. single-phase induction motor

Description : A shaded-pole motor is a ____________. A. synchronous motor B. three-phase induction motor C. compound-wound motor D. single-phase induction motor

Last Answer : Answer: D

The synchronous speed for a 3 phase 6-pole induction motor is 1200 rpm. If the number of poles is now reduced to 4 with the frequency remaining constant, the rotor speed with a slip of 5% will be _________. (A) 1690 rpm (B) 1750 rpm (C) 1500 rpm (D) 1710 rpm

Description : The synchronous speed for a 3 phase 6-pole induction motor is 1200 rpm. If the number of poles is now reduced to 4 with the frequency remaining constant, the rotor speed with a slip of 5% will be _________. (A) 1690 rpm (B) 1750 rpm (C) 1500 rpm (D) 1710 rpm

Last Answer : (D) 1710 rpm

Salient-pole rotors may be used in alternators driven by what types of prime movers?

Description : Salient-pole rotors may be used in alternators driven by what types of prime movers?

Last Answer : Internal combustion engines, water force and electric motors

Consider the following statements : 1. Salient pole alternators have small diameters and large axial lengths....

Description : Consider the following statements :  1. Salient pole alternators have small diameters and large axial lengths.  2. Cylindrical rotor alternators have a distributed winding.  3. Cylindrical rotor alternators are wound for large number ... 3 only (b) 2 and 4 only (c) 1 and 4 only (d) 2 and 3 only

Last Answer : Consider the following statements :  1. Salient pole alternators have small diameters and large axial lengths.  2. Cylindrical rotor alternators have a distributed winding.  3. Cylindrical rotor alternators are wound for ... 3 only (b) 2 and 4 only (c) 1 and 4 only (d) 2 and 3 only

Salient pole rotor is use for which speed?

Description : Salient pole rotor is use for which speed?

Last Answer : Salient pole rotor is use for low and medium speed prime movers.

In a triangle, ABC, if `cos A + cos B + 4 cos C=4," then find the value of "(a+b)/(c).` [Note : All symbols used have their usual meaning in triangle

Description : In a triangle, ABC, if `cos A + cos B + 4 cos C=4," then find the value of "(a+b)/(c).` [Note : All symbols used have their usual meaning in triangle

Last Answer : In a triangle, ABC, if `cos A + cos B + 4 cos C=4," then find the value of "(a+ ... Note : All symbols used have their usual meaning in triangle ABC.]

The angle of twist for the equivalent bar to a spring is given by? (Symbols have their usual meaning) a) 8PD2N/Gd4 b) 16PD2N/Gd4 c) 16PDN/Gdɜ d) 8PDN/Gdɜ

Description : The angle of twist for the equivalent bar to a spring is given by? (Symbols have their usual meaning) a) 8PD2N/Gd4 b) 16PD2N/Gd4 c) 16PDN/Gdɜ d) 8PDN/Gdɜ

Last Answer : b) 16PD2N/Gd4

The angle of twist for the equivalent bar to a spring is given by? (Symbols have their usual meaning) a) 8PD²N/Gd⁴ b) 16PD²N/Gd⁴ c) 16PDN/Gdᵌ d) 8PDN/Gdᵌ

Description : The angle of twist for the equivalent bar to a spring is given by? (Symbols have their usual meaning) a) 8PD²N/Gd⁴ b) 16PD²N/Gd⁴ c) 16PDN/Gdᵌ d) 8PDN/Gdᵌ

Last Answer : b) 16PD²N/Gd⁴

Longitudinal stress in a cylinder is given by [symbols have their usual meanings]. a) PD/2t b) 2PD/t c) PD/4t d) 4PD/t

Description : Longitudinal stress in a cylinder is given by [symbols have their usual meanings]. a) PD/2t b) 2PD/t c) PD/4t d) 4PD/t

Last Answer : c) PD/4t

Tangential stress in a cylinder is given by [symbols have their usual meanings]. a) PD/2t b) 2PD/t c) PD/4t d) 4PD/t

Description : Tangential stress in a cylinder is given by [symbols have their usual meanings]. a) PD/2t b) 2PD/t c) PD/4t d) 4PD/t

Last Answer : a) PD/2t

A 12 -pole, 440 V, 50 Hz, 3 -phase synchronous motor takes a line current of 100 A at 0.8 pf leading....

Description : A 12 -pole, 440 V, 50 Hz, 3 -phase synchronous motor takes a line current of 100 A at 0.8 pf leading. Neglecting losses, the torque developed will be

Last Answer : A 12 -pole, 440 V, 50 Hz, 3 -phase synchronous motor takes a line current of 100 A at 0.8 pf leading. Neglecting losses, the torque developed will be 1165 Nm

The difference between the synchronous speed of an induction machine and its operating speed (slip) may be correctly expressed _____________. A. as a percent of synchronous speed B. as a decimal fraction of synchronous speed C. directly in revolutions per minute D. as all of the above

Description : The difference between the synchronous speed of an induction machine and its operating speed (slip) may be correctly expressed _____________. A. as a percent of synchronous speed B. as a decimal fraction of synchronous speed C. directly in revolutions per minute D. as all of the above

Last Answer : Answer: A

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

Mention the uses of damper windings in a synchronous machine?

Description : Mention the uses of damper windings in a synchronous machine?

Last Answer : 1. Damper winding is used to reduce the oscillations developed in the rotor of alternator when it is suddenly loaded. 2. The damper winding is used to start the synchronous motor as an induction motor.

What are the essential features of synchronous machine?

Description : What are the essential features of synchronous machine?

Last Answer : i. The rotor speed is synchronous with stator rotating field. ii. Varying its field current can easily vary the speed. iii. It is used for constant speed operation.

Why a 3-phase synchronous machine will always run at synchronous speed?

Description : Why a 3-phase synchronous machine will always run at synchronous speed?

Last Answer : Because of the magnetic coupling between the stator poles and rotor poles the motor runs exactly at synchronous speed.

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

The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous machine. (D) single phase induction machine.

Description : The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous machine. (D) single phase induction machine.

Last Answer : Ans: all options are correct

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

A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged? A. Overspeed trip B. Thermal overload relay C. Three-pole safety switch D. Magnetic blowout coil

Description : A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged? A. Overspeed trip B. Thermal overload relay C. Three-pole safety switch D. Magnetic blowout coil

Last Answer : Answer: B

Which one of the following statements for a dc machine which is provided with inter pole winding (IW) as well as compensating winding (CW) is correct a) Both IW and CW are connected in series with Armature winding b) Both IW and CW are connected in parallel with Armature winding c) IW connected in series but CW is connected in parallel with Armature winding d) CW connected in series but IW is connected in parallel with Armature winding

Description : Which one of the following statements for a dc machine which is provided with inter pole winding (IW) as well as compensating winding (CW) is correct a) Both IW and CW are connected in ... parallel with Armature winding d) CW connected in series but IW is connected in parallel with Armature winding

Last Answer : Ans: Both IW and CW are connected in series with Armature winding

What are the salient features of distribution transformer?

Description : What are the salient features of distribution transformer?

Last Answer : 1. The distribution transformer will have low iron loss and higher value of copper loss 2. The capacity of transformers will be up to 500 KVA 3. The transformers will have plain walled ... with cooling tubes or radiators. 4. The leakage reactance and regulation will be low.

What are the salient features of IPBD?

Description : What are the salient features of IPBD?  

Last Answer : a. This for a vital link between generator, GT, UAT, SPPT, SET and neutral grounding transformer. b. The continuous enclosure operating at ground potential limits the leakage flux outside the enclosure ... maintenance is nil. j. Separate parts erected IPBD. Hence changing parts makes it easy. 

Is the Roku 2 XD streaming player compatible with the Buffalo LS-WX2.0TL/R1 LinkStation Duo NAS drive's DLNA server?

Description : Is the Roku 2 XD streaming player compatible with the Buffalo LS-WX2.0TL/R1 LinkStation Duo NAS drive's DLNA server?

Last Answer : answer:Anything that's DLNA certified should work with any Buffalo product, but I can't say for certain if Roku's are tested. Buffalo NAS devices are tested with Windows, OS X, PS 3, and XBox 360s and I've ... I'll ask today. If we don't, I'll suggest doing so just to see how far that gets.

How do you explain the concept of the Disney XD logo to someone?

Description : How do you explain the concept of the Disney XD logo to someone?

Last Answer : Disney XD

What exactly is "XD" supposed to represent in online text speak?

Description : What exactly is "XD" supposed to represent in online text speak?

Last Answer : X = squinting eyes D = huge smile

How much lube should I put on my Springfield XD-40 after cleaning?

Description : How much lube should I put on my Springfield XD-40 after cleaning?

Last Answer : answer:Just coat all the internal parts as thinly as possible. You don't need to lubricate, just prevent corrosion. If you use a water-based cleaner, make sure everything is completely dry before oiling. ... next to it. I sometimes carry a subcompact (like a .45 ACP derringer) in an ankle holster.

In Fig.5.7, AC = XD, c is the mid-point of AB and D is the mid-point of XY. Using a Euclid's axiom,show that AB=XY. -Maths 9th

Description : In Fig.5.7, AC = XD, c is the mid-point of AB and D is the mid-point of XY. Using a Euclid's axiom,show that AB=XY. -Maths 9th

Last Answer : Solution :-

What does xd mean?

Description : I wonder what the meaning and origin of the term "xd" so often used today is.

Last Answer : XD should be capitalized. It is, after all, a symbol of a laughing head, X replaces the shrinking eyes, and D replaces the laughing mouth. I guess so you’ve figured out that this is used when they react to something very funny.       

Are the new Fujifilm cameras still able to use an xD card?

Description : Are the new Fujifilm cameras still able to use an xD card?

Last Answer : Yes the new cameras do, Here is some more information http://www.fujifilm.com/products/digital_cameras/accessories/card/ No, the new Fujifilm cameras do not use xD cards anymore. Fujifilm has decided to phase the xD cards in order to replace them with SD cards.

What do I look for when purchasing a xD Card?

Description : What do I look for when purchasing a xD Card?

Last Answer : It all depends on what you want to get out of the memory card. Depending on how many pictures you would like to be able to keep on it at one time and the mega pixels of your camera the size you ... would hold in a 5mp camera. The more megapixels a camera has the more space each photo will take up.

Can I play the Disney xd games for free?

Description : Can I play the Disney xd games for free?

Last Answer : You are able to play the Disney XD Games for free. Simply go to Disney.go.com and you will have access to all of the Disney Channel games.