89 views

1 Answer

Answer :

Exciters of synchronous machines are d.c. shunt machines.

Like 0 like

Please log in or register to answer this question.

Related questions

102 views

Last Answer : Slip-rings in a synchronous motor carry direct current.

1 answer
77 views

Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.

1 answer
176 views

Description : 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.

1 answer
203 views

Last Answer : A synchronous motor running with normal excitation adjusts to load increases essentially by increase in armature current.

1 answer
101 views

Last Answer : The standard full-load power factor ratings for synchronous motors are unity or 0.8 leading.

1 answer
98 views

Last Answer : Synchronsizing power of a synchronous machine is inversely proportional to the synchronous reactance.

1 answer
125 views

Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.

1 answer
118 views

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.

1 answer
261 views

Last Answer : In case one phase of a three-phase synchronous motor is short-circuited the motor will not start.

1 answer
95 views

Last Answer : Synchronous motors are generally not self-starting because the direction of instantaneous torque reverses after half cycle.

1 answer
150 views

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

1 answer
200 views

Last Answer :  The size of a synchronous motor decreases with the increase in flux density.

1 answer
154 views

Last Answer : The duration of sudden short-circuit test on a synchronous motor is usually about one second.

1 answer
308 views

Description : 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.

1 answer
107 views

Last Answer : A synchronous machine with low value of short-circuit ratio has lower stability limit.

1 answer
87 views

Last Answer : The construction of a synchronous motor resembles an alternator.

1 answer
264 views

Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.

1 answer
112 views

Last Answer : For power factor correction, synchronous motors operate at no-load and greatly over-excited fields.

1 answer
106 views

Description : 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?

0 answers
227 views

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.

1 answer
121 views

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.

1 answer
111 views

Last Answer : The armature current of the synchronous motor has large values for low and high excitation.

1 answer
97 views

Description : Which motor have more efficiency, synchronous motor or induction motor?

Last Answer : Synchronous motor has more efficiency.

1 answer
129 views

Description : If we change the excitation of synchronous machine will it affect on power factor?

Last Answer : Yes, If we change the excitation of synchronous machine it will affect on power factor. If the synchronous motor is overexcited then it will have leading power factor and if the motor is underexcited then it will have lagging power factor.

1 answer
108 views

Description : 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.

1 answer
310 views

Description : 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.

1 answer
1.5k views

Description : 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.

1 answer
158 views

Description : 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.

1 answer
81 views

Description : V - curve of synchronous machine shows the relation between?

Last Answer : V - curve of synchronous machine shows the relation between AC armature current and DC field current.

1 answer
3.4k views

Description : Why synchronous machine is called doubly excited machine?

Last Answer : Armature windings of synchronous machines either deliver 3 phase AC or absorb 3 phase AC source,  whereas field windings are energized from DC source. Thus due to presence of AC on armature and DC on field windings, synchronous machines are often referred as doubly excited machines.

2 answers
101 views

Description : Hunting in synchronous motor cannot be due to?

Last Answer : Hunting in synchronous motor cannot be due to windage friction.

1 answer
72 views

Description : Which machine is the exciter of synchronous machine?

Last Answer : DC shunt machine is the exciter of synchronous machine.

1 answer
176 views

Description : 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.

1 answer
162 views

Description : 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.

1 answer
507 views

Description : 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.

1 answer
170 views

Description : An unexcited single phase synchronous motor is ?

Last Answer : An unexcited single-phase synchronous motor is reluctance motor.

1 answer
132 views

Description : A synchronous motor can be made self starting by providing?

Last Answer : A synchronous motor can be made self-starting by providing damper bar.

1 answer
106 views

Description : In a synchronous motor which losses varies with load?

Last Answer : In a synchronous motor, copper losses varies with load.

1 answer
70 views

Description : The back emf of synchronous motor depends on?

Last Answer : The back emf of synchronous motor depends on load angle.

1 answer
95 views

Description : Synchronous motor always runs at which speed?

Last Answer : Synchronous motor always runs at synchronous speed.

1 answer
92 views

Description : 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.

1 answer
249 views

Description : 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.

1 answer
377 views

Description : 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.

1 answer
97 views

Description : Three phase synchronous motor will have how many sliprings?

Last Answer : Three phase synchronous motor will have two sliprings.

1 answer
1 view

Description : Are we losing control over our life to machines?

Last Answer : That is up to you. You can or you can decide to not.

1 answer
15 views

Description : Heat Transfer Machines

Last Answer : Heat transfer machines are just the thing you need in order to do heat transfers on your clothing or whatever surface you want to decorate. In order for you to stick designs and precious stones on porous and ... is best. This will also give you an idea of what kind of designs you can choose from.

1 answer
69 views

Description : Write measures to be taken to maintain the insulation resistance of electrical machines to healthy levels.

0 answers
112 views

Description : What type of motor is used for drilling machines?

Last Answer : universal motor also used in Handheld power tools, blowers, blenders, vacuum cleaners, polishers and kitchen appliances.universal motor is defined as a motor which may be operated either on direct or single phase AC supply at approximately the same speed and output

1 answer
1.5k views

Description : The inertia constants of two groups of machines which do not swing together are M1 and M2. The equivalent inertia constant of the system is

Last Answer : The inertia constants of two groups of machines which do not swing together are M1 and M2. The equivalent inertia constant of the system is M1M2/M1+M2

1 answer
305 views

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Last Answer : 3  Commutation

2 answers
...