In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as (1) synchronous motor (2) synchronous generator (3) asynchronous motor (4) asynchronous generator
Last Answer : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as synchronous generator
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May 1, 2018
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anonymous

The direction of rotation of an inverter fed 3-phase ac motor is reversed by (A) a mechanical reversing switch (B) reversing the input dc link voltage (C) operating the inverter as a rectifier (D) changing the sequence of switching
Last Answer : The direction of rotation of an inverter fed 3-phase ac motor is reversed by changing the sequence of switching
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Apr 28, 2018
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anonymous

Last Answer : The direction of rotation of a D.C. series motor can be changed by interchanging field terminals.
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185 views
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Mar 20, 2018
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anonymous

Last Answer : The direction of rotation of universal motor can be reversed the by reversing the flow of current through either armature winding or field winding.
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249 views
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Mar 20, 2018
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anonymous

Last Answer : In case of a shaded pole motor the direction of rotation of the motor is from main pole to shaded pole.
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338 views
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Mar 20, 2018
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anonymous
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Last Answer : Direction of rotation of a split phase motor can be reversed by reversing the connection of either running winding or starting winding.
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357 views
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Mar 20, 2018
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anonymous

Last Answer : The direction of rotation of an hysteresis motor is determined by position of shaded pole with respect to main pole.
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230 views
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Mar 20, 2018
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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
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Mar 20, 2018
by
anonymous

What happens when you reverse the direction of the current in an electromagnet?
Last Answer : When you reverse current direction in an electromagnet, the magnetic poles will also change.
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Mar 14, 2018
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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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131 views
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Mar 20, 2018
by
anonymous

how can we reverse the direction of rotation of three phase induction motor ?
Last Answer : The direction of rotation of three phase induction motor can be reversed by plugging i.e by changing any two out of three phases of the supply to the stator of the Induction motor terminal.
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137 views
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Oct 4, 2017
by
anonymous

If we change the excitation of synchronous machine will it affect on motor speed?
Last Answer : No, If we change the excitation of synchronous machine it will not affect on motor speed.
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105 views
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Mar 18, 2018
by
anonymous

Can we use the synchronous motor as the synchronous capacitor?
Last Answer : Yes, we can use the synchronous motor as the synchronous capacitor when the synchrnous motor is overexcited.
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Mar 18, 2018
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anonymous

Last Answer : Slip-rings in a synchronous motor carry direct current.
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Mar 20, 2018
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anonymous
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Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.
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Mar 20, 2018
by
anonymous

A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because?
Last Answer : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because stator supply is not required to produce magnetic field.
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169 views
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Mar 20, 2018
by
anonymous

Last Answer : A synchronous motor running with normal excitation adjusts to load increases essentially by increase in armature current.
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195 views
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Mar 20, 2018
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anonymous
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Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.
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Mar 20, 2018
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anonymous

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.
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Mar 20, 2018
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anonymous

Last Answer : In case one phase of a three-phase synchronous motor is short-circuited the motor will not start.
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254 views
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Mar 20, 2018
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anonymous

Last Answer : In a synchronous motor, the armature current has large values for high and low excitation.
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138 views
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Mar 20, 2018
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anonymous

Last Answer : The size of a synchronous motor decreases with the increase in flux density.
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Mar 20, 2018
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anonymous

Last Answer : The duration of sudden short-circuit test on a synchronous motor is usually about one second.
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1 answer
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Mar 20, 2018
by
anonymous

The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?
Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.
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Mar 20, 2018
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anonymous

Last Answer : The construction of a synchronous motor resembles an alternator.
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1 answer
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Mar 20, 2018
by
anonymous

Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.
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257 views
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Mar 20, 2018
by
anonymous

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as?
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106 views
0 answers
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Mar 20, 2018
by
anonymous

Last Answer : The coupling angle or load angle of synchronous motor is defined as the angle between the rotor and the stator poles of opposite polarity.
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Mar 20, 2018
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anonymous

Last Answer : If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the stator current will be zero.
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116 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The armature current of the synchronous motor has large values for low and high excitation.
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107 views
1 answer
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Mar 20, 2018
by
anonymous

Which motor have more efficiency, synchronous motor or induction motor?
Last Answer : Synchronous motor has more efficiency.
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Mar 18, 2018
by
anonymous

What is the maximum value of torque angle in synchronous motor?
Last Answer : The maximum value of torque angle in synchronous motor is 90 degrees electrical.
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Mar 18, 2018
by
anonymous

If the load of the normally excited synchronous motor is increased the power factor will?
Last Answer : If the load of the normally excited synchronous motor is increased the power factor will become lagging.
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1 answer
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Mar 18, 2018
by
anonymous

Hunting in synchronous motor cannot be due to?
Last Answer : Hunting in synchronous motor cannot be due to windage friction.
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Mar 18, 2018
by
anonymous

The synchronous motor which works on leading power factor and does not drive any mechanical load is called?
Last Answer : The synchronous motor which works on leading power factor and does not drive any mechanical load is called synchronous condenser.
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162 views
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Mar 18, 2018
by
anonymous

The damping winding in synchronous motor is generally used to?
Last Answer : The damping winding in synchronous motor is generally used to provide starting torque and prevent hunting.
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157 views
1 answer
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Mar 18, 2018
by
anonymous

If the field of synchronous motor is under excited, power factor will be?
Last Answer : If the field of synchronous motor is under excited, power factor will be lagging.
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483 views
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Mar 18, 2018
by
anonymous

An unexcited single phase synchronous motor is ?
Last Answer : An unexcited single-phase synchronous motor is reluctance motor.
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Mar 18, 2018
by
anonymous

A synchronous motor can be made self starting by providing?
Last Answer : A synchronous motor can be made self-starting by providing damper bar.
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131 views
1 answer
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Mar 18, 2018
by
anonymous

In a synchronous motor which losses varies with load?
Last Answer : In a synchronous motor, copper losses varies with load.
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Mar 18, 2018
by
anonymous

The back emf of synchronous motor depends on?
Last Answer : The back emf of synchronous motor depends on load angle.
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Mar 18, 2018
by
anonymous

Synchronous motor always runs at which speed?
Last Answer : Synchronous motor always runs at synchronous speed.
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Mar 18, 2018
by
anonymous

The synchronous motor will develop maximum power when the load angle is?
Last Answer : The synchronous motor will develop maximum power when the load angle is 900.
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223 views
1 answer
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Mar 18, 2018
by
anonymous

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.
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367 views
1 answer
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Mar 18, 2018
by
anonymous

Three phase synchronous motor will have how many sliprings?
Last Answer : Three phase synchronous motor will have two sliprings.
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Mar 18, 2018
by
anonymous

In a single-phase induction motor, the operating direction is determined by the ________ A) Rotor B) Stator C) Starting circuit D) None of these
Last Answer : In a single-phase induction motor, the operating direction is determined by the Starting circuit
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Apr 29, 2018
by
anonymous
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How can we improve power factor using synchronous motor?
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0 answers
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Mar 15, 2018
by
anonymous

Last Answer : Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.
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Mar 6, 2018
by
anonymous

List different starting methods of three phase synchronous motor. Explain any one of them.
Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor.
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May 7, 2020
by
anonymous

Draw and explain V and inverted V curves for synchronous motor.
Last Answer : V curves' and inverted V curves' for Synchronous Motor: V curve: V curve is a plot of the stator current versus field current for different constant loads. The graph is plotted ... Vcurves of synchronous motor. The highest point on each of these curves indicates unity power factor.
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May 7, 2020
by
anonymous
