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

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
.jpg)
Last Answer : In a synchronous motor, the armature current has large values for high and low excitation.
Show More
138 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
.jpg)
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

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

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
.jpg)
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
.jpg)
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

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

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
.jpg)
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
.jpg)
A three-phase synchronous motor connected to ac mains is running at full load and unity power factor. lf its shaft load is reduced by half and field current is held constant then its new power factor will be
Last Answer : Leading
Show More
564 views
2 answers
asked
Apr 28, 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.
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

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

The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is (A) 0.25 pu (B) 0.5 pu (C) 1.0 pu (D) 1.5 pu
Last Answer : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is 0.5 pu
Show More
98 views
1 answer
asked
Apr 28, 2018
by
anonymous

The effect of increasing load on a synchronous motor running with normal excitation is (A) Increase both its Ia and power factor. (B) Decrease Ia, but increase power factor. (C) Increase Ia, but decrease power factor (D) Decrease both Ia and power factor.
Last Answer : The effect of increasing load on a synchronous motor running with normal excitation is Increase Ia, but decrease power factor
Show More
548 views
1 answer
asked
Apr 28, 2018
by
anonymous

Last Answer : In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will run as induction motor.
Show More
111 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.
Show More
222 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in damage to the starting winding.
Show More
129 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : An over excited synchronous motor on noload is known as synchronous condenser.
Show More
77 views
1 answer
asked
Mar 20, 2018
by
anonymous

Why synchronous motor Cannot start itself?
Show More
75 views
0 answers
asked
Mar 15, 2018
by
anonymous
.jpg)
How can we improve power factor using synchronous motor?
Show More
78 views
0 answers
asked
Mar 15, 2018
by
anonymous

What is the principle of synchronous motor?
Show More
74 views
0 answers
asked
Mar 15, 2018
by
anonymous
