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

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
Show More
193 views
1 answer
asked
Apr 29, 2018
by
anonymous

A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is
Last Answer : A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is 36 Ohm
Show More
331 views
1 answer
asked
May 3, 2018
by
anonymous

Last Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.
Show More
367 views
1 answer
asked
Mar 20, 2018
by
anonymous

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
Show More
601 views
1 answer
asked
May 1, 2018
by
anonymous

The armature reaction in a synchronous generator supplying leading power factor load is (A) magnetizing (B) demagnetizing (C) demagnetizing and cross-magnetizing (D) magnetizing and cross-magnetizing
Last Answer : The armature reaction in a synchronous generator supplying leading power factor load is magnetizing and cross-magnetizing
Show More
96 views
1 answer
asked
Apr 28, 2018
by
anonymous

Last Answer : Slip-rings in a synchronous motor carry direct current.
Show More
99 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.
Show More
73 views
1 answer
asked
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.
Show More
169 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A synchronous motor running with normal excitation adjusts to load increases essentially by increase in armature current.
Show More
195 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.
Show More
121 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.
Show More
114 views
1 answer
asked
Mar 20, 2018
by
anonymous

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

Last Answer : The size of a synchronous motor decreases with the increase in flux density.
Show More
196 views
1 answer
asked
Mar 20, 2018
by
anonymous

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

Last Answer : The construction of a synchronous motor resembles an alternator.
Show More
83 views
1 answer
asked
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.
Show More
257 views
1 answer
asked
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?
Show More
106 views
0 answers
asked
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.
Show More
218 views
1 answer
asked
Mar 20, 2018
by
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.
Show More
116 views
1 answer
asked
Mar 20, 2018
by
anonymous
.jpg)
Which motor have more efficiency, synchronous motor or induction motor?
Last Answer : Synchronous motor has more efficiency.
Show More
93 views
1 answer
asked
Mar 18, 2018
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.
Show More
105 views
1 answer
asked
Mar 18, 2018
by
anonymous

How can we reverse the direction of rotation of synchronous motor?
Last Answer : By reversing supply phase sequence we can reverse the direction of rotation of synchronous motor.
Show More
305 views
1 answer
asked
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.
Show More
1.5k views
1 answer
asked
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.
Show More
150 views
1 answer
asked
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.
Show More
96 views
1 answer
asked
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.
Show More
162 views
1 answer
asked
Mar 18, 2018
by
anonymous
.jpg)
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.
Show More
157 views
1 answer
asked
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.
Show More
483 views
1 answer
asked
Mar 18, 2018
by
anonymous

An unexcited single phase synchronous motor is ?
Last Answer : An unexcited single-phase synchronous motor is reluctance motor.
Show More
160 views
1 answer
asked
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.
Show More
131 views
1 answer
asked
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.
Show More
102 views
1 answer
asked
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.
Show More
65 views
1 answer
asked
Mar 18, 2018
by
anonymous

Synchronous motor always runs at which speed?
Last Answer : Synchronous motor always runs at synchronous speed.
Show More
90 views
1 answer
asked
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.
Show More
91 views
1 answer
asked
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.
Show More
223 views
1 answer
asked
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.
Show More
367 views
1 answer
asked
Mar 18, 2018
by
anonymous

Three phase synchronous motor will have how many sliprings?
Last Answer : Three phase synchronous motor will have two sliprings.
Show More
95 views
1 answer
asked
Mar 18, 2018
by
anonymous

The normal value of the armature resistance of a d.c. motor is?
Last Answer : The normal value of the armature resistance of a d.c. motor is 0.5.
Show More
2.9k views
1 answer
asked
Mar 26, 2018
by
anonymous

Last Answer : When the armature of a D.C. motor rotates, e.m.f. induced is back e.m.f.
Show More
203 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The armature voltage control of D.C. motor provides constant torque drive.
Show More
92 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.
Show More
210 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a A.C. series motor armature coils are usually connected to commutator through resistance.
Show More
161 views
1 answer
asked
Mar 20, 2018
by
anonymous

Armature control of DC motor
Last Answer : Armature control of DC motor
Show More
162 views
2 answers
asked
Aug 9, 2017
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.
Show More
157 views
1 answer
asked
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.
Show More
498 views
1 answer
asked
May 7, 2020
by
anonymous

List different torques in synchronous motor.
Last Answer : Different Torques in Synchronous Motor: 1) Starting torque 2) Running torque 3) Pull-in torque 4) Pull-out torque
Show More
115 views
1 answer
asked
May 7, 2020
by
anonymous
.jpg)
Damper winding in a synchronous motor
Last Answer : Damper winding in a synchronous motor Serves to start the motor.
Show More
87 views
1 answer
asked
May 8, 2018
by
anonymous

In a self-controlled synchronous motor fed from a variable frequency inverter (1) the rotor poles invariably have damper windings (2) there are stability problems (3) the speed of the rotor decides stator frequency (4) the frequency of the stator decides the rotor speed
Last Answer : 2
Show More
636 views
2 answers
asked
Apr 29, 2018
by
anonymous
