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why induction motor is called rotating transformer?

why induction motor is called rotating transformer?

351 views

asked Aug 22, 2017 by anonymous

1 Answer

Answer :

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

answered Dec 16, 2017 by Electrical kida

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Related Questions

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

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

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asked Apr 29, 2018 by anonymous

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

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

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asked Apr 28, 2018 by anonymous

Why Induction motor is called rotating transformer?

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.

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asked Dec 24, 2021 by itszee

what is mean by rotating transformer ?

what is mean by rotating transformer ?
Last Answer : Induction motor is a rotating transformer

91 views 1 answer

asked Aug 19, 2017 by anonymous

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

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

16 views 1 answer

asked Jan 4 by itszee

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

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

7 views 1 answer

asked Jan 4 by itszee

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

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

3 views 1 answer

asked Jan 4 by itszee

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

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

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asked Jan 4 by itszee

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

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

2 views 1 answer

asked Jan 4 by itszee

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

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.

259 views 1 answer

asked Jan 6, 2021 by anonymous

Define rotating magnetic field of an induction motor.

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.

68 views 1 answer

asked Jun 3, 2020 by anonymous

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

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

219 views 1 answer

asked May 17, 2018 by anonymous

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

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

509 views 1 answer

asked Mar 31, 2018 by anonymous

Split phase induction motor

Split phase induction motor
Last Answer : Split phase induction motor : There are two windings used in split phase induction motor. It is a type of single-phase induction motor. There are two winding one is called main winding and ... motor have low starting torque it is used for small fans, blowers, centrifugal pumps, grinders etc.

232 views 1 answer

asked Sep 20, 2018 by anonymous

The starting torque of a V/f controlled inverter-fed 3-phase induction motor operating at 25 Hz as compared

The starting torque of a V/f controlled inverter-fed 3-phase induction motor operating at 25 Hz as compared with the same motor operating at 50 Hz is (A) more (B) double (C) equal (D) less

61 views 0 answers

asked Jun 4, 2018 by anonymous

In slip-energy recovery scheme of converter-fed 3-phase induction motor, super synchronous speeds are

In slip-energy recovery scheme of converter-fed 3-phase induction motor, super synchronous speeds are possible by (A) injecting voltage into the stator (B) injecting voltage into the rotor (C) extracting voltage from the stator (D) extracting voltage from the rotor.

70 views 0 answers

asked Jun 4, 2018 by anonymous

A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging.

A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the ... the motor will be (A) 23.06 kW (B) 24.11 kW (C) 25.01 kW (D) 26.21 kW
Last Answer : A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the core losses are 1200 W. The air-gap power of the motor will be 25.01 kW

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asked May 17, 2018 by anonymous

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

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

458 views 1 answer

asked May 17, 2018 by anonymous

In a double squirrel cage induction motor, good starting torque is produced as

In a double squirrel cage induction motor, good starting torque is produced as (A) Large current flows through the outer high resistance winding. (B) Large current flows through the inner high ... the outer high resistance winding. (D) Large current flows through the inner low resistance winding.
Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.

137 views 1 answer

asked May 8, 2018 by anonymous

A change of 4% in the supply voltage to an induction motor will produce a change of approximately

A change of 4% in the supply voltage to an induction motor will produce a change of approximately
Last Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque

485 views 1 answer

asked May 8, 2018 by anonymous

In an induction motor if the flux density is reduced to one-half, of its normal value then the torque will

In an induction motor if the flux density is reduced to one-half, of its normal value then the torque will (1) reduce to one-half (2) reduce to one-fourth (3) remain unchanged (4) increase four times
Last Answer : In an induction motor if the flux density is reduced.to one-half, of its normal value then the torque will reduce to one-fourth

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asked May 1, 2018 by anonymous

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

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

237 views 1 answer

asked May 1, 2018 by anonymous

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

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

161 views 1 answer

asked Apr 29, 2018 by anonymous

Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to

Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be
Last Answer : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be 25 N -m

427 views 1 answer

asked Apr 29, 2018 by anonymous

A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for

A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for
Last Answer : A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for 4 poles

307 views 1 answer

asked Apr 29, 2018 by anonymous

In a split-phase induction motor, the resistance/reactance ratios of windings are such that

In a split-phase induction motor, the resistance/reactance ratios of windings are such that (A) current in the auxiliary winding leads the current in the main winding (B) current in the ... (C) both windings develop the same starting torque (D) both windings develop high starting current
Last Answer : In a split-phase induction motor, the resistance/reactance ratios of windings are such that current in the auxiliary winding leads the current in the main winding

107 views 1 answer

asked Apr 28, 2018 by anonymous

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then (A) the flux is constant (B) the flux first decreases and then increases in ... increases and decreases in the opposite direction with the same magnitude (D) current flows through the rotor
Last Answer : In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then the flux first decreases and then increases in the same direction

95 views 1 answer

asked Apr 28, 2018 by anonymous

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

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

179 views 1 answer

asked Apr 28, 2018 by anonymous

The torque developed by any 3-phase induction motor at 0.8 p.u. slip is

The torque developed by any 3-phase induction motor at 0.8 p.u. slip is (A) Full-load torque (B) unstable torque (C) starting torque (D) break down
Last Answer : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is unstable torque

3.1k views 1 answer

asked Apr 28, 2018 by anonymous

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

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

168 views 1 answer

asked Apr 28, 2018 by anonymous

The rotor winding of a three phase wound rotor induction motor is equipped with a three phase diode...

The rotor winding of a three phase wound rotor induction motor is equipped with a three phase diode rectifier connected to the slip rings and rectifier output is connected with chopper drive. Compared to ... B) Maintains the motor rating as such C) Derates the motor D) None of the above

90 views 0 answers

asked Apr 9, 2018 by anonymous

After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on?

Last Answer : Reason is kinetic energy

289 views 2 answers

asked Mar 20, 2018 by anonymous

If starting winding of a single-phase induction motor is left in the circuit, it will?

Last Answer : If starting winding of a single-phase induction motor is left in the circuit, it will draw excessive current and overheat.

236 views 1 answer

asked Mar 20, 2018 by anonymous

If a single phase induction motor runs slower than normal, the most likely defect is?

Last Answer : If a single phase induction motor runs slower than normal, the most likely defect is worn bearings.

170 views 1 answer

asked Mar 20, 2018 by anonymous

The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it?

Last Answer : The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it helps in reducing the tendency of the rotor teeth to remain under the stator teeth.

146 views 1 answer

asked Mar 20, 2018 by anonymous

Speed torque characteristic of a repulsion induction motor is similar to that of a D.C.?

Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.

169 views 1 answer

asked Mar 20, 2018 by anonymous

How is a three phase cage induction motor self starting?

How is a three phase cage induction motor self starting?
Last Answer : Any type of induction motor is self starting. Because the reason for torqe production require two flux displaced by some angle theta.If theta is constant with time then torqe will be constant;if ... torqe also pulsating. In induction motor this angle theta is not pulsating.so it is self starting

160 views 1 answer

asked Mar 17, 2018 by anonymous

How does a single phase induction motor work?

How does a single phase induction motor work?
Last Answer : As we know that single phase induction is not self started because for self started we require atleast two revolving field but single phase induction motor has only one. So we provide extra ... 1phase IM classified as split phase IM, capacitor start capacitor run, capacitor start induction run.

124 views 1 answer

asked Mar 17, 2018 by anonymous

Is induction motor is self starting?

Is induction motor is self starting?
Last Answer : Single phase induction motor is not self starting. Three phase induction motor is self starting.

111 views 1 answer

asked Mar 17, 2018 by anonymous

What is the definition of induction motor?

What is the definition of induction motor?
Last Answer : its working on magnetic base made by coils and its work with 1 phase or 3 phase ac or dc supply

123 views 1 answer

asked Mar 17, 2018 by anonymous

What is the function of induction motor?

What is the function of induction motor?
Last Answer : while you give supply to motor its motor run on magnet base

160 views 1 answer

asked Mar 17, 2018 by anonymous

At which time power factor of the induction motor is low?

At which time power factor of the induction motor is low?
Last Answer : The power factor of the inducction motor is low at the time of starting as compare to while the induction motor is running.

151 views 1 answer

asked Mar 3, 2018 by anonymous

What is mean by plugging in three phase induction motor?

What is mean by plugging in three phase induction motor?
Last Answer : Plugging in three-phase induction motor means interchanging of any two phases of a stator for quick stopping.

156 views 1 answer

asked Mar 3, 2018 by anonymous

explain the working of single phase induction motor.

explain the working of single phase induction motor.
Last Answer : Stator has two winding namely main winding and auxiliary winding.when single phase ac supply is given to the motor,its produces alternating field.this field cut by a cage rotor.so some emf ... due to this emf,rotor flux produced.the interaction between two fluxes produce torque.so rotor rotates.

188 views 1 answer

asked Oct 24, 2017 by anonymous

which single phase induction motor has highest starting torque?

Last Answer : Capacitor start motor has high torque in starting

136 views 1 answer

asked Sep 13, 2017 by anonymous

is induction motor ac or dc?

Last Answer : Induction motor is a AC motor it is also known as asynchronous motor .

100 views 1 answer

asked Sep 9, 2017 by anonymous

can induction motor be used as generator?

Last Answer : if induction motor rotates exceed than its synchronous speed, it acts as a generator.

68 views 1 answer

asked Sep 9, 2017 by anonymous

Induction motor

Induction motor
Last Answer : Induction Motor Inductor is a coil of wire which possess the property of inductance. Inductance is the property of an electric conductor which generate electromotive force (EMF ... motor are classified as slip ring induction motor and squirrel cage induction motor.

79 views 1 answer

asked Aug 9, 2017 by anonymous

Single Phase Induction Motor

Single Phase Induction Motor
Last Answer : Single Phase Induction Motor Single phase induction motor is mostly used in home, office, shop and many single phase appliances like pumps, ... torque and silent operation. It is uses where silent operation is required.

528 views 1 answer

asked Aug 9, 2017 by anonymous

Types of three phase induction motor rotor

Types of three phase induction motor rotor
Last Answer : Types of three phase induction motor rotorSquirrel cage rotor : There are two types of three phase induction motor rotor one is squirrel cage rotor and second is wound rotor. About 80 to ... control of three phase induction motor via rotor resistance control method is possible with this rotor.

146 views 1 answer

asked Aug 9, 2017 by anonymous

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