For the speed control purpose, pole changing method can be adopted for

For the speed control purpose, pole changing method can be adopted for
by

1 Answer

Answer :

For the speed control purpose, pole changing method can be adopted for Squirrel cage induction motor

by

Related questions

Explain speed control method of 3 phase induction motor by the following methods: (1) Pole changing (2) Rotor resistance control (3) Stator voltage

Description : Explain speed control method of 3 phase induction motor by the following methods: (1) Pole changing (2) Rotor resistance control (3) Stator voltage

Last Answer : 1) Pole Changing Method:  Synchronous speed is given by, From the above equation of synchronous speed, it can be seen that synchronous speed (and hence, running speed) can ... in voltage and consequently the speed decreases and vice versa. Ultimately speed depends on the supply voltage.

The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min

Description : The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min (A) 100 rpm (B) 200 rpm (C) 400 rpm (D) 800 rpm

Last Answer : The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min 200 rpm

A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor

Description : A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor rotates at a speed of ________ rpm with respect to stator field. (A) 1500 (B) 0 (C) 1440 (D) 60

Last Answer : 0

Speed control by Ward Leonard method gives uniform speed variation?

Last Answer : Speed control by Ward Leonard method gives uniform speed variation in both directions.

A pole pitch in electrical machine is:

Description : A pole pitch in electrical machine is: (1) Equal to 180° electrical (2) Equal to 180° mechanical (3) Less than 180° electrical (4) Greater Than 180° electrical

Last Answer : A pole pitch in electrical machine is: Equal to 180° electrical

A 4-pole, 3-phase, double-layer winding is housed in a 36-slot stator for an ac machine with

Description : A 4-pole, 3-phase, double-layer winding is housed in a 36-slot stator for an ac machine with 60o phase spread. Coil span is 7 short pitches. Number of slots in which top and bottom layers belong to different phases is  (A) 24 (B) 18 (C) 12 (D) 0

Last Answer : A 4-pole, 3-phase, double-layer winding is housed in a 36-slot stator for an ac machine with 60o phase spread. Coil span is 7 short pitches. Number of slots in which top and bottom layers belong to different phases is 24 

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated

Description : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor ... Hz supply is  (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

Last Answer : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A 

Total electrical degrees for a 4 pole AC machine is equal to

Description : Total electrical degrees for a 4 pole AC machine is equal to

Last Answer : Total electrical degrees for a 4 pole AC machine is equal to 720 ̊

A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and

Description : A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively

Last Answer : A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively 19,17

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

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 slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is

Description : The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is 

Last Answer : The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is 4 percent

The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors

Description : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is  (1) 1000V (2) 100V (3) 600V (4) 10,000V

Last Answer : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is 1000V

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

An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW.

Description : An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is (A) 5.06 kW (B) 0.3 kW (C) 100 kW (D) 83.33 kW

Last Answer : An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is 83.33 kW

Locked rotor current of a shaded pole motor is?

Last Answer : Locked rotor current of a shaded pole motor is slightly more than full load current.

The shaded pole motor is used for?

Last Answer : The shaded pole motor is used for low starting torque.

Which of the following methods may be adopted to reduce the effects of armature reaction ? (a) Increase in length of air gap at pole tips (b) Increasing reluctance of pole tips (c) Compensating windings (d) Interpoles (e) All of the above

Description : Which of the following methods may be adopted to reduce the effects of armature reaction ? (a) Increase in length of air gap at pole tips (b) Increasing reluctance of pole tips (c) Compensating windings (d) Interpoles (e) All of the above

Last Answer : (e) All of the above

What do you think about changing the names of adopted children?

Description : What do you think about changing the names of adopted children?

Last Answer : if they want them to choose their own names, their current names should be one of the choices

In the question a part of the sentence is given in BOLD. Alternatives to the BOLD part are given which may improve the construction of the sentence. Select the correct alternative. He admired the speed with which he completed the work and appreciating the method adopted by him (a) appreciate the method being adopted (b) appreciated the method adopted (c) appreciate the method of adoption (d) appreciated the method adopting method

Description : In the question a part of the sentence is given in BOLD. Alternatives to the BOLD part are given which may improve the construction of the sentence. Select the correct alternative. He admired ... the method adopted (c) appreciate the method of adoption (d) appreciated the method adopting method

Last Answer : (b) appreciated the method adopted

A 4-point starter is used to start and control the speed of a

Description : A 4—point starter is used to start and control the speed of a  A) DC shunt motor with armature resistance control B) DC shunt motor with field weakening control C) DC series motor D) Thyristor controlled d.c. motor

Last Answer : A 4—point starter is used to start and control the speed of a DC shunt motor with armature resistance control 

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control

Description : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases 

Which motor has the poorest speed control?

Last Answer : Series motor has the poorest speed control.

Usually wide and sensitive speed control is desired in case of?

Last Answer : Usually wide and sensitive speed control is desired in case of colliery winders.

Speed control of a universal motor is achieved by?

Last Answer : Speed control of a universal motor is achieved by varying field flux with tapped field windings, connecting rheostat in series, applying variable voltage by means of silicon controlled rectifier, applying variable voltage by means of variable auto-transformer.

The speed control of universal motor used for sewing machines is by?

Last Answer : The speed control of universal motor used for sewing machines is by varying the resistance.

What are the speed control methods of dc motor?

Description : What are the speed control methods of dc motor?

Last Answer : Field control of DC motor Armature control of DC motor

speed control methods of three phase induction motor?

Description : speed control methods of three phase induction motor?

Last Answer : Speed control of three phase induction motor

The purpose of the bias winding in figure 'B' shown in the illustration is for ____________. EL-0091 A. changing the direction of current in the control winding B. setting the operating point of the device C. allowing the use of either AC or DC in the load circuit D. changing the direction of current through the load

Description : The purpose of the bias winding in figure 'B' shown in the illustration is for ____________. EL-0091 A. changing the direction of current in the control winding B. setting the operating point of the ... use of either AC or DC in the load circuit D. changing the direction of current through the load

Last Answer : Answer: B

A degree of control over the speed of a slip ring induction motor can be obtained by _____________. A. adjusting governor linkage B. changing the number of phases to the motor C. inserting resistance into the stator circuit D. inserting resistance into the rotor circuit

Description : A degree of control over the speed of a slip ring induction motor can be obtained by _____________. A. adjusting governor linkage B. changing the number of phases to the motor C. inserting resistance into the stator circuit D. inserting resistance into the rotor circuit

Last Answer : Answer: D

The purpose of stator winding in the compensated repulsion motor is to?

Last Answer : The purpose of stator winding in the compensated repulsion motor is to improve power factor and provide better speed regulation.

When was the ‘International Convention on the Elimination of All Forms of Racial Dis-crimination’ adopted and to what purpose? -SST 10th

Description : When was the ‘International Convention on the Elimination of All Forms of Racial Dis-crimination’ adopted and to what purpose? -SST 10th

Last Answer : The General Assembly adopted the International Convention on the Elimination of All Forms of Racial Discrimination' in December, 1965. The convention came into force in 1969 and as its name suggests ... to Racial Discrimination in all its forms. It was mandatory for the States who ratified it.

What is the purpose of static starter? How current setting adopted?

Description : What is the purpose of static starter? How current setting adopted?

Last Answer : The static starter limits the starting current of the motor to 2.5 times the motor rated current instead of 6 times the rated current. If the motor is directly on UPS, the UPS fuse will blow, ... set to limit the starting current. This is achieved by firing angle control of back to back thyristor. 

Farmers also adopted sprinkaler system for purpose. A) Commercial. C) Domestic

Description : Farmers also adopted sprinkaler system for purpose. A) Commercial. C) Domestic

Last Answer : Commercial.

A tight-rope walker carries a long pole which he holds across his body. The purpose of this pole is to------? A. Prop him up if he falls B. Spread out his weight and reduce the pressure on the rope C. Add extra weight to keep the rope tightly stretched D. To keep the centre of gravity always vertically above the rope (Answer)

Description : A tight-rope walker carries a long pole which he holds across his body. The purpose of this pole is to------? A. Prop him up if he falls B. Spread out his weight and reduce the ... to keep the rope tightly stretched D. To keep the centre of gravity always vertically above the rope (Answer)

Last Answer : D. To keep the centre of gravity always vertically above the rope (Answer)

A tight-rope walker carries a long pole which he holds across his body. The purpose of this pole is to-----? A. Prop him up if he falls B. Spread out his weight and reduce the pressure on the rope C. Add extra weight to keep the rope tightly stretched D. To keep the Center of gravity always above vertically above the rope (Answer)

Description : A tight-rope walker carries a long pole which he holds across his body. The purpose of this pole is to-----? A. Prop him up if he falls B. Spread out his weight and reduce the ... keep the rope tightly stretched D. To keep the Center of gravity always above vertically above the rope (Answer)

Last Answer : D. To keep the Center of gravity always above vertically above the rope (Answer)

The purpose of a ‘satellite station’ in triangulation can be served by : (a) A ‘Church spire’ in order to secure a well- shaped triangle (b) A ‘Flag pole’ in order to secure a well- shaped triangle (c) A ‘Steeple’ in order to secure a well- shaped triangle (d) An ‘Eccentric station’ near the true station whereon the instrument cannot be setup

Description : The purpose of a satellite station' in triangulation can be served by : (a) A Church spire' in order to secure a well- shaped triangle (b) A Flag pole' in order to secure a well- ... a well- shaped triangle (d) An Eccentric station' near the true station whereon the instrument cannot be setup

Last Answer : (d) An ‘Eccentric station’ near the true station whereon the instrument cannot be setup

Which method of braking is generally used in elevators ?

Last Answer : Plugging method of braking is generally used in elevators.

For very low speed and high power applications the best suited ac motor is:

Description : For very low speed and high power applications the best suited ac motor is:

Last Answer : For very low speed and high power applications the best suited ac motor is: synchronous motor

For a 1.8, 2-phase bipolar stepper motor, the stepping rate is 100 steps/second. The rotational speed of the

Description : For a 1.8o, 2-phase bipolar stepper motor, the stepping rate is 100 steps/second. The rotational speed of the motor in rpm is  (A) 15 (B) 30 (C) 60 (D) 90

Last Answer : For a 1.8o, 2-phase bipolar stepper motor, the stepping rate is 100 steps/second. The rotational speed of the motor in rpm is 30 

The torque speed characteristic of a repulsion motor resembles which of the following d.c. motor

Description : The torque speed characteristic of a repulsion motor resembles which of the following d.c. motor characteristics  A) Separately excited B) Shunt C) Series D) Compound

Last Answer : The torque speed characteristic of a repulsion motor resembles which of the following d.c. motor characteristics Series 

A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s.

Description : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be

Last Answer : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be 474 V

The fall in speed of a dc generator due to increase in load can be corrected by

Description : The fall in speed of a dc generator due to increase in load can be corrected by  (1) cooling the armature.. (2) increasing the excitation. (3) reducing the load voltage. (4) increasing the input to the prime mover

Last Answer : It   can  be  corrected  by  increasing  the  input  to  the  prime  mover.

In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an

Description : In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is (A) 0.2 Ω (B) 0.3 Ω (C) 0.4 Ω (D) 0.5 Ω

Last Answer : In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is 0.3 Ω

In variable speed motor?

Last Answer : In variable speed motor a weaker commutating field is needed at low speed than at high speed.

The speed of a D.C. motor can be controlled by varying

Description : The speed of a D.C. motor can be controlled by varying  1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above

Last Answer : The speed of a D.C. motor can be controlled by varying  1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above

In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will?

Last Answer : In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will remain unchanged.

The speed of a D.C. shunt motor can be increased by?

Last Answer : The speed of a D.C. shunt motor can be increased by increasing the resistance in field circuit.

As the load is increased the speed of D.C. shunt motor will?

Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.