Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.
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165 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Explain the working of a single phase capacitor start induction motor.
Last Answer : Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc
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398 views
2 answers
asked
Jul 30, 2019
by
anonymous

Last Answer : In a capacitor start and run motors the function of the running capacitor in series with the auxiliary winding is to improve power factor.
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712 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In repulsion motor direction of rotation of motor is the same as that of brush shift.
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116 views
1 answer
asked
Mar 20, 2018
by
anonymous

Which type of starter is used to start the DC motor?
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77 views
0 answers
asked
Mar 15, 2018
by
anonymous

State starters used for i) 3-Ph squirrel cage induction motor (3HP) ii) D.C. motor
Last Answer : Name the starters used for following motors : i) 3 H.P. 3-Ph squirrel cage I.M: i) DOL starter OR ii) Star-Delta Starter OR ii) Auto transformer starter OR iii) Soft start starter. ii) D.C Shunt Motor : 1) Armature resistance starter (Three Point Starter) OR 2) Four Point Starter
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154 views
1 answer
asked
Sep 18, 2018
by
anonymous

Last Answer : A universal motor can run on either A.C. or D.C.
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71 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : A schrage motor can run on zero slip, negative slip, positive slip.
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67 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A repulsion motor is equipped with commutator.
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123 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Last Answer : In repulsion motor, zero torque is developed when brush axis coincides with the field axis and brush axis is 90° electrical to field axis.
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97 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Last Answer : The purpose of stator winding in the compensated repulsion motor is to improve power factor and provide better speed regulation.
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110 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In repulsion motor, maximum torque is developed when brush axis is at 45° electrical to the field axis.
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116 views
1 answer
asked
Mar 20, 2018
by
anonymous

A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will?
Last Answer : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will not start at all.
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232 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a capacitor start single-phase motor, when capacitor is replaced by a resistance motor will continue to run in same direction.
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223 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Last Answer : In a capacitor start motor, the phase displacement between starting and running winding can be nearly 90°.
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207 views
1 answer
asked
Mar 20, 2018
by
anonymous

The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be?
Last Answer : The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be 4.
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143 views
1 answer
asked
Mar 26, 2018
by
anonymous

Last Answer : Single phase induction motor usually operates on 0.6 power factor lagging.
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127 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A single-phase induction motor is inherently non-self-starting with low torque.
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73 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The power factor of a single-phase induction motor is usually lagging.
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191 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a ceiling fan employing capacitor run motor secondary winding surrounds the primary winding.
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101 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Reason is kinetic energy
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285 views
2 answers
asked
Mar 20, 2018
by
anonymous

Last Answer : To reverse the direction of rotation of a capacitor start motor while it is running we should disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding.
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132 views
1 answer
asked
Mar 20, 2018
by
anonymous

Why synchronous motor Cannot start itself?
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75 views
0 answers
asked
Mar 15, 2018
by
anonymous

Last Answer : In a two value capacitor motor, the capacitor used for running purposes is paper spaced oil filled type.
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162 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Last Answer : The motor used on small lathes is usually single-phase capacitor run motor.
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147 views
1 answer
asked
Mar 20, 2018
by
anonymous
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Last Answer : A shaded pole motor can be used for toys, hair dryers, circulators etc.
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103 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A centrifugal switch is used to disconnect starting winding when motor has picked up about 50 to 70 per cent of rated speed.
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879 views
1 answer
asked
Mar 20, 2018
by
anonymous

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.
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146 views
1 answer
asked
Mar 20, 2018
by
anonymous

The range of frequencies used in induction heating is : (A) 0-25 Hz (C) less than 200 Hz (B) 50 to 100 Hz (D) more than 1 kHz
Last Answer : The range of frequencies used in induction heating is : more than 1 kHz
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100 views
1 answer
asked
Apr 29, 2018
by
anonymous

Last Answer : For handling greater currents induction wattmeters are used in conjunction with current transformers.
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139 views
1 answer
asked
Mar 21, 2018
by
anonymous

Basic electrical engineering
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12 views
0 answers

Explain the working principle of induction motor.
Last Answer : Working principle of induction motor: * When the motor is excited with three-phase supply, three-phase stator winding carries three-phase currents & produces a rotating magnetic field of constant magnitude and ... , which tend to move the rotor in the same direction as the rotating magnetic field.
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588 views
1 answer
asked
May 22, 2020
by
anonymous

Explain the activities carried out during weekly maintenance of 3 ph. Induction motor.
Last Answer : Activities Carried out During Weekly Maintenance of 3 ph. Induction Motor: 1) Check belt tension. In cases where this is excessive it should immediately be reduces and in the case of sleeve ... and cooled by oil mist systems its important to check the oil mist flow paths/pressure components.
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163 views
1 answer
asked
May 7, 2020
by
anonymous
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State the function of following parts in Induction motor. (i) Stator (ii) Slip rings
Last Answer : Name of part Function Stator 1) Stator frame supports the core, terminal box and protects the inner parts. 2) Stator core houses stator winding. 3) Stator winding ... ) Provides facility to connect external resistance to rotor circuit through brushes for starting and control.
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221 views
1 answer
asked
May 7, 2020
by
anonymous

List the energy conservation technique in induction motor.
Last Answer : Following are the list of energy conservation techniques in electrical motors: 1) Reduction in iron losses by using low loss silicon steel core material laminated to thinner dimension. 2) Using bigger length ... at light load. 13) By rewinding in induction motor 14) By motor survey
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1.1k views
1 answer
asked
May 3, 2020
by
anonymous

With a neat sketch give the working of shaded pole induction motor.
Last Answer : Explanation: It has squirrel cage rotor and salient pole stator. The stator poles are shaded partially by short circuited conductor band to create the phase difference between the fluxes emerging from shaded ... rotating magnetic field in the air-gap and torque is exerted on the squirrel cage rotor.
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265 views
2 answers
asked
Apr 27, 2020
by
anonymous

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.
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133 views
0 answers
asked
Apr 16, 2020
by
anonymous

Explain the need and steps to conduct the reduced voltage running up test on the three phase induction motor.
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222 views
0 answers
asked
Apr 16, 2020
by
anonymous

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
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113 views
3 answers
asked
Aug 18, 2019
by
anonymous
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Define Slip of Induction Motor.
Last Answer : Slip: It is the ratio of relative speed of rotor (difference between synchronous speed and rotor speed) to the synchronous speed of rotating magnetic field. Slip = (NS – N) / NS where , NS = synchronous speed, N = speed of rotor
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59 views
1 answer
asked
Aug 17, 2019
by
anonymous

State any four advantages of three phase induction motor.
Last Answer : Advantages of three phase induction motor https://youtu.be/27OIOCKN05U
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138 views
2 answers
asked
Jul 30, 2019
by
anonymous

Last Answer : Energy conservation technique in induction motor by minimizing idle and redundant running of motor: 1) Loss of energy as the no load power drawn is approximately about 12% to 16% of rated ... to unnecessary line losses. 4) Reduction in overall system energy efficiency over period of time.
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691 views
1 answer
asked
Sep 22, 2018
by
anonymous

State and explain any four factors governing selection of induction motor.
Last Answer : The factors governing the selection of Induction motor: 1) Load torque required at normal speed matches with available torque of motor. 2) Break down torque or pull out torque or maximum torque ... If selecting energy efficient motor the cost benefit analysis over the long run must be worked out.
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2.8k views
1 answer
asked
Sep 22, 2018
by
anonymous

Explain energy conservation technique “by improving power quality” for induction motor.
Last Answer : Energy conservation method in induction motor by improving power quality: Electrical energy can be conserved by improving the power quality. It can be achieved by avoiding voltage unbalance, maintaining ... losses can be minimized by using harmonic filter thus reducing the harmonics in the system.
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3.6k views
2 answers
asked
Sep 22, 2018
by
anonymous

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.
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230 views
1 answer
asked
Sep 20, 2018
by
anonymous

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.
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136 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
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
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467 views
1 answer
asked
May 8, 2018
by
anonymous

The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be
Last Answer : The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be 0.5 Ohm
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165 views
1 answer
asked
May 3, 2018
by
anonymous

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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372 views
1 answer
asked
May 1, 2018
by
anonymous

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
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235 views
1 answer
asked
May 1, 2018
by
anonymous
