The speed of the rotating magnetic field in an induction motor is known as the_____.

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Answer :

The speed of the rotating magnetic field in an induction motor is known as the synchronous speed.

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Related questions

Define rotating magnetic field of an induction motor.

Description : Define rotating magnetic field of an induction motor. 

Last Answer : Rotating magnetic field of an induction motor: A rotating magnetic field is a magnetic field that has moving polarities in which its opposite poles rotate about a central point or axis.

In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage supply to the stator windings C. laminated steel core and aluminum conductors in the rotor D. interaction of the magnetic field caused by the induced current in the squirrel-cage bars with the magnetic field of the stator

Description : In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage ... caused by the induced current in the squirrel-cage bars with the magnetic field of the stator

Last Answer : Answer: B

Explain how in a 3 phase induction motor to a rotating magnetic field is developed.

Description : Explain how in a 3 phase induction motor to a rotating magnetic field is developed. 

Last Answer : Production of Rotating Magnetic Field in Three-phase Induction Motor: In three-phase induction motor, the three-phase stator windings are displaced in space by 120° and their three-phase currents are displaced ... time by 120°. Such fluxes give rise to the resultant rotating magnetic field.

The synchronous speed of an induction motor is the ________. A. speed at which the rotor turns B. speed of the rotating field C. frequency of the rotor current D. slip in per cent of rotor RPM

Description : The synchronous speed of an induction motor is the ________. A. speed at which the rotor turns B. speed of the rotating field C. frequency of the rotor current D. slip in per cent of rotor RPM

Last Answer : Answer: B

Regarding an induction motor, the power developed by the rotor automatically adjusts itself to the _____________. A. power required to drive the load B. speed required to drive the load C. current flow in the motor stator D. torque developed by the rotating field

Description : Regarding an induction motor, the power developed by the rotor automatically adjusts itself to the _____________. A. power required to drive the load B. speed required to drive the load C. current flow in the motor stator D. torque developed by the rotating field

Last Answer : Answer: A

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

The direction of rotation of an induction motor is ________. A. opposite the rotating field direction B. the same as the direction of the rotating field C. determined by the number of poles D. determined by the staggering of the brushes

Description : The direction of rotation of an induction motor is ________. A. opposite the rotating field direction B. the same as the direction of the rotating field C. determined by the number of poles D. determined by the staggering of the brushes

Last Answer : Answer: B

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

What is the main function in the use of a capacitor for starting a single phase motor? A. Reduce radio interference B. Split the phase to establish a rotating magnetic field C. Reduce the phase angle D. Prolong the life of the starting contacts

Description : What is the main function in the use of a capacitor for starting a single phase motor? A. Reduce radio interference B. Split the phase to establish a rotating magnetic field C. Reduce the phase angle D. Prolong the life of the starting contacts

Last Answer : Answer: B

The rotor of a synchronous motor operates in synchronism with the rotating field because ______________. A. of the amortisseur windings B. the rotor is magnetically locked into step with the rotating magnetic field by the excitation current C. the field strength varies directly with rotor slip D. the stator flux rotates in the opposite direction

Description : The rotor of a synchronous motor operates in synchronism with the rotating field because ______________. A. of the amortisseur windings B. the rotor is magnetically locked into step with the ... field strength varies directly with rotor slip D. the stator flux rotates in the opposite direction

Last Answer : Answer: B

What determines the number of field poles required to establish a rotating magnetic field in a multiphase motor stator?

Description : What determines the number of field poles required to establish a rotating magnetic field in a multiphase motor stator?

Last Answer : The number of phases in the applied voltage.

In an induction type energy meter, the steady speed attained by the rotating disc is

Description : In an induction type energy meter, the steady speed attained by the rotating disc is  1. Proportional to the deflecting torque. 2. Proportional to the resistance of the path of eddy currents. 3. ... 4. Inversely proportional to the square of brake magnet flux.  Which of the above are correct ?

Last Answer : In an induction type energy meter, the steady speed attained by the rotating disc is 1. Proportional to the deflecting torque. 2. Proportional to the resistance of the path of eddy currents. 3. Inversely proportional to ... brake magnet flux. Which of the above are correct ? 1, 2, 3 and 4 

A charged particle is rotating in uniform circular motion in a uniform magnetic field . Let r= radius of circule, v= speed of particle k = kinetic ene

Description : A charged particle is rotating in uniform circular motion in a uniform magnetic field . Let r= radius of circule, v= speed of particle k = kinetic ene

Last Answer : A charged particle is rotating in uniform circular motion in a uniform magnetic field . Let r ... angular speed. then match the following two columns.

The most practical way to control the voltage output of an AC generator is to vary the _____________. A. number of windings B. speed of the rotating field C. strength of the rotating magnetic field D. power factor of the load

Description : The most practical way to control the voltage output of an AC generator is to vary the _____________. A. number of windings B. speed of the rotating field C. strength of the rotating magnetic field D. power factor of the load

Last Answer : Answer: C

Why Induction motor is called rotating transformer?

Description : Why Induction motor is called rotating transformer?

Last Answer : Transformer has two sides: primary & secondary. Transformer transforms energy from primary to secondary by induction. Similarly, Induction motor has primary (stator) & secondary (rotor). Voltage is ... magnitude i.e. the process of induction Thus induction motor treated as a rotating transformer.

A 4-pole induction motor, supplied by a slightly unbalanced three-phase 50 Hz source, is rotating at 1440

Description : A 4-pole induction motor, supplied by a slightly unbalanced three-phase 50 Hz source, is rotating at 1440 rpm. The electrical frequency in Hz of the induced negative sequence current in the rotor is  (A) 100 (B) 98 (C) 52 (D) 48

Last Answer : A 4-pole induction motor, supplied by a slightly unbalanced three-phase 50 Hz source, is rotating at 1440 rpm. The electrical frequency in Hz of the induced negative sequence current in the rotor is 98 

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

why induction motor is called rotating transformer?

Description : why induction motor is called rotating transformer?

Last Answer : Induction motor works on same principal as transformers work ie faradays law of electromagnetic induction. ie IM called as rotating transformer 

A shunt motor rotating at 1500 r/min is fed by a 120 V source. The line current is 51 A and the shunt field...

Description : A shunt motor rotating at 1500 r/min is fed by a 120 V source. The line current is 51 A and the shunt field resistance is 120 ohm. If the armature resistance is 0.1 ohm, calculate the current in the armature.  (A) 1 A (B) 51 A (C) 50 A (D) 12 A 

Last Answer : C

Under normal conditions, the speed of a two-speed squirrel cage induction motor is changed by varying the ____________. A. frequency of the applied voltage B. resistance in the rotor circuit C. number of field poles D. amplitude of the applied voltage

Description : Under normal conditions, the speed of a two-speed squirrel cage induction motor is changed by varying the ____________. A. frequency of the applied voltage B. resistance in the rotor circuit C. number of field poles D. amplitude of the applied voltage

Last Answer : Answer: C

The speed of a wound-rotor induction motor _____________. A. will be fixed by the number of field poles B. can be varied by a rheostat-type control C. can only be synchronous speed at full load D. can only attain synchronous speed at no load

Description : The speed of a wound-rotor induction motor _____________. A. will be fixed by the number of field poles B. can be varied by a rheostat-type control C. can only be synchronous speed at full load D. can only attain synchronous speed at no load

Last Answer : Answer: B

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

In Induction motor Slip frequency of rotor current, when rotor speed is Nr. Then rotor producing slip field rotates with respect to stator is a) Slip frequency b) Nr c) Ns d) None

Description : In Induction motor Slip frequency of rotor current, when rotor speed is Nr. Then rotor producing slip field rotates with respect to stator is a) Slip frequency b) Nr c) Ns d) None

Last Answer : Ans: Ns

in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure:

Description : in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure: 

Last Answer : in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure: At synchronous speed in the direction of stator field

There is a ring of radius r having linear charge density `lambda` and rotating with a uniform angular velocity `omega.` the magnetic field produced by

Description : There is a ring of radius r having linear charge density `lambda` and rotating with a uniform angular velocity `omega.` the magnetic field produced by

Last Answer : There is a ring of radius r having linear charge density `lambda` and rotating with a uniform angular velocity ` ... D. `(mu_(0)lambda)/(2omega^(2))`

Assertion A charged particle is rotating in a circle. Then magnetic field (B) at centre of circle and magnetic moment (M) produced by motion of charge

Description : Assertion A charged particle is rotating in a circle. Then magnetic field (B) at centre of circle and magnetic moment (M) produced by motion of charge

Last Answer : Assertion A charged particle is rotating in a circle. Then magnetic field (B) at centre of circle and ... M and B are always parallel to each other.

Assertion A charged particle is rotating in a circular path in uniform magnetic field. Then, plane of circle is perpendicular to the magnetic field. R

Description : Assertion A charged particle is rotating in a circular path in uniform magnetic field. Then, plane of circle is perpendicular to the magnetic field. R

Last Answer : Assertion A charged particle is rotating in a circular path in uniform magnetic field. Then, plane of ... . If Assertion is false but Reason is true.

Assertion If a charged particle enters from outside in uniform magnetic field, then it will keep on rotating in a circular path. Reson Magnetic force

Description : Assertion If a charged particle enters from outside in uniform magnetic field, then it will keep on rotating in a circular path. Reson Magnetic force

Last Answer : Assertion If a charged particle enters from outside in uniform magnetic field, then it will keep on ... . If Assertion is false but Reason is true.

What does a Rotating magnetic field do?

Description : What does a Rotating magnetic field do?

Last Answer : Rotating magnetic field induces the voltage in the statorwinding under which the rotor is rotating. refer Faraday's law.

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

What is the direction of rotation of rotor with respect to the rotating magnetic field?

Description : What is the direction of rotation of rotor with respect to the rotating magnetic field?

Last Answer : Answer: Rotating Magnetic Field is set up when 3 phase ac supply is provided to the stator windings of the induction motor. Rotating Magnetic Field rotates at synchronous speed. Rotor rotates in the direction of the rotating magnetic field

A synchronous motor maintains synchronism with the rotating field because _____________. A. field strength varies directly with rotor slip B. DC current applied to the rotor coils causes the rotor magnets to lock in with the rotating flux of the stator C. the stator poles are dragged around due to the flux created by the excitation current D. the stator flux rotates in the opposite direction

Description : A synchronous motor maintains synchronism with the rotating field because _____________. A. field strength varies directly with rotor slip B. DC current applied to the rotor coils causes the rotor ... the flux created by the excitation current D. the stator flux rotates in the opposite direction

Last Answer : Answer: B

On some diesel-electric ships, the DC propulsion motor will only attain half speed when the generator fields are fully excited. Speeds above this are obtained by _____________. A. rotating brush alignment B. raising the generator engine speed C. lowering the generator engine speed D. decreasing excitation

Description : On some diesel-electric ships, the DC propulsion motor will only attain half speed when the generator fields are fully excited. Speeds above this are obtained by _____________. A. rotating brush ... B. raising the generator engine speed C. lowering the generator engine speed D. decreasing excitation

Last Answer : Answer: B

When the torque required by the machine is more than the torque supplied by the motor, the flywheel is (A) Accelerated (B) Retarded (C) Rotating with constant speed (D) Any of the above

Description : When the torque required by the machine is more than the torque supplied by the motor, the flywheel is (A) Accelerated (B) Retarded (C) Rotating with constant speed (D) Any of the above

Last Answer : (B) Retarded

What will happen if the induction motor runs at synchronous speed ?

Description : What will happen if the induction motor runs at synchronous speed ?

Last Answer : Since there is always slip present in rotor it cannot run at synchronous speed no current will be developed hence no torque will developed

A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage...

Description : A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage drops to 90% of the rated value, % increase in motor copper losses  (a) 23% (b) -18% (c) 123% (d) None of these

Last Answer : A three phase induction motor is driving full -load torque which is independent of speed. If the line voltage drops to 90% of the rated value, % increase in motor copper losses (a) 23% (b) -18% (c) 123% (d) None of these

In a variable speed induction motor derive V/f kept constant over a wide range of its frequency variation. ...

Description :  In a variable speed induction motor derive V/f kept constant over a wide range of its frequency variation. The motor operates in the following mode : -  a) Constant power mode b) Constant torque mode c) Constant slip mode d) Variable power and variable torque mode

Last Answer :  In a variable speed induction motor derive V/f kept constant over a wide range of its frequency variation. The motor operates in the following mode : - Constant torque mode

A 50 Hz, 3—phase induction motor has a full load speed of 1440 rpm. The number of poles of the motor is: ...

Description : A 50 Hz, 3—phase induction motor has a full load speed of 1440 rpm. The number of poles of the motor is:   (A)4 (8)6 (0)12  (D)8

Last Answer : Ans: A N= Ns (1-S) = NS –NS x S 1440 = Ns (1-S) Ns = 1440 / (1-S) Ns = (120 f/ p) = 120 x 50/p = 6000 p Ns will be closer to N i.e 1440 When P=2 ; Ns = 3000 rpm , not close to N When P=4 ; Ns = 1500 rpm , it is closer to N Therefore P =4 for N=1440

The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

Description : The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

Last Answer : Ns         equals        f/pair pole 50/4      - 12.5

The speed of the rotor is always somewhat less than the speed of the rotating field. What is the difference called?

Description : The speed of the rotor is always somewhat less than the speed of the rotating field. What is the difference called?

Last Answer : Slip.

Which of the following statements is true concerning the operating characteristics of a squirrel-cage motor? A. Rotor slip is dependent upon the motor load. B. An increase in motor load results in less slip. C. A decrease in rotor speed results in less generated current. D. A decrease in rotor speed produces a weaker magnetic field.

Description : Which of the following statements is true concerning the operating characteristics of a squirrel-cage motor? A. Rotor slip is dependent upon the motor load. B. An increase in motor load results in ... results in less generated current. D. A decrease in rotor speed produces a weaker magnetic field.

Last Answer : Answer: A

The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor

Description : The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor

Last Answer : Answer: C

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

What is magnetic locking or cogging effect of induction motor?

Description : What is magnetic locking or cogging effect of induction motor?

Last Answer : In squirrel cage induction motor some times the rotor and stator care teeth or slots are comes face to face or parallel at stationary condition. If we are starting the motor at this condition the motor ... the rotor slot, such that there is no common factor between the rotor slot and stator slots.

a. The P wave represent the electrical excitation of the_____ b. The QRS complex represents the ____ of the ventricles. c. The end of T wave marks the

Description : a. The P wave represent the electrical excitation of the_____ b. The QRS complex represents the ____ of the ventricles. c. The end of T wave marks the

Last Answer : a. The P wave represent the electrical excitation of the_____ b. The QRS complex represents the ____ of ... The end of T wave marks the end of _____

a. The P wave represent the electrical excitation of the_____ b. The QRS complex represents the ____ of the ventricles. c. The end of T wave marks the

Description : a. The P wave represent the electrical excitation of the_____ b. The QRS complex represents the ____ of the ventricles. c. The end of T wave marks the

Last Answer : a. The P wave represent the electrical excitation of the_____ b. The QRS complex represents the ____ of ... The end of T wave marks the end of _____

The_____ of kidney produce a peptide hormone called____which stimulates_____.

Description : The_____ of kidney produce a peptide hormone called____which stimulates_____.

Last Answer : The_____ of kidney produce a peptide hormone called____which stimulates_____.

In Bluetooth, the_____ link is used when data integrity is more important than avoiding latency. A) SCO B) ACL C) ACO D) SCL

Description : In Bluetooth, the_____ link is used when data integrity is more important than avoiding latency. A) SCO B) ACL C) ACO D) SCL

Last Answer : ACL

In Bluetooth, the_____ link is used when avoiding latency (delay in data delivery) is more important than integrity (error-free delivery). A) SCO B) ACL C) ACO D) SCL

Description : In Bluetooth, the_____ link is used when avoiding latency (delay in data delivery) is more important than integrity (error-free delivery). A) SCO B) ACL C) ACO D) SCL

Last Answer : SCO

The ________form of the malarial parasite enters the human blood while The_____ enters the mosquito. a. Sporozoites; Merozoites b. Merozoites; Gametocytes c. Merozoites; Sporozoites d. Sporozoites; Gametocytes

Description : The ________form of the malarial parasite enters the human blood while The_____ enters the mosquito. a. Sporozoites; Merozoites b. Merozoites; Gametocytes c. Merozoites; Sporozoites d. Sporozoites; Gametocytes

Last Answer : d. Sporozoites; Gametocytes