Answer :
In case one phase of a three-phase synchronous motor is short-circuited the motor will not start.
asked
Mar 20, 2018
by
anonymous
Description : Three phase synchronous motor will have how many sliprings?
Answer :
Three phase synchronous motor will have two sliprings.
asked
Mar 18, 2018
by
anonymous
Description : State suitable single phase motor for following applications: (i) Table fan (ii) Mixers and Grinders
Answer :
Application Suitable Single Phase Motor Table Fan 1) Capacitor split phase motor 2) Capacitor start capacitor run motor Mixers and Grinders 1) Universal motor 2) A.C. Series motor
asked
May 7, 2020
by
anonymous
Description : Why is a capacitor used in a single phase motor and not in three phase motor ?
Answer :
In 1-phase induction motor capacitor work is generate the auxiliary winding current than excite the main winding to rotor starts rotate. After rotor start rotating about 75% of their speed than auxiliary ... emf to start the motor.so,in 3-phase induction motor is self start induction motor.
asked
Sep 2, 2019
by
anonymous
Description : working principle of single phase motor
Answer :
The Stator of single phase induction motor houses two windings 1. Main (Running) winding 2. Auxiliary (Starting ) winding Rotor of single phase induction motor is ... with starting winding or a capacitor may be permanently connected in series with Auxiliary (Starting ) winding.
asked
Aug 21, 2019
by
anonymous
Description : Explain the working of a single phase capacitor start induction motor.
Answer :
Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc
asked
Jul 30, 2019
by
anonymous
Description : What is the slip (as a percentage) when a 6 pole single phase induction motor operating on 220 V and 60 Hz is rotating at speed of 1140 rpm? A) 60% B) 5% C) 10% D) None of these
Answer :
What is the slip (as a percentage) when a 6 pole single phase induction motor operating on 220 V and 60 Hz is rotating at speed of 1140 rpm? A) 60% B) 5% C) 10% D) None of these
asked
Apr 29, 2018
by
anonymous
Answer :
Reason is kinetic energy
asked
Mar 20, 2018
by
anonymous
Answer :
If a single phase induction motor runs slower than normal, the most likely defect is worn bearings.
asked
Mar 20, 2018
by
anonymous
Answer :
Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a magnetic relay.
asked
Mar 20, 2018
by
anonymous
Answer :
Single phase induction motor usually operates on 0.6 power factor lagging.
asked
Mar 20, 2018
by
anonymous
Description : 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?
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.
asked
Mar 20, 2018
by
anonymous
Description : The running winding of a single phase motor on testing with meggar is found to be ground. Most probable location of the ground will be?
Answer :
The running winding of a single phase motor on testing with meggar is found to be ground. Most probable location of the ground will be at the slot edge where coil enters or comes out of the slot.
asked
Mar 20, 2018
by
anonymous
Answer :
In a single phase motor the centrifugal switch disconnects auxiliary winding of the motor.
asked
Mar 20, 2018
by
anonymous
Description : How does a single phase induction motor work?
Answer :
As we know that single phase induction is not self started because for self started we require atleast two revolving field but single phase induction motor has only one. So we provide extra ... 1phase IM classified as split phase IM, capacitor start capacitor run, capacitor start induction run.
asked
Mar 17, 2018
by
anonymous
Description : explain the working of single phase induction motor.
Answer :
Stator has two winding namely main winding and auxiliary winding.when single phase ac supply is given to the motor,its produces alternating field.this field cut by a cage rotor.so some emf ... due to this emf,rotor flux produced.the interaction between two fluxes produce torque.so rotor rotates.
asked
Oct 24, 2017
by
anonymous
Description : Single Phase Induction Motor
Answer :
Single Phase Induction Motor Single phase induction motor is mostly used in home, office, shop and many single phase appliances like pumps, ... torque and silent operation. It is uses where silent operation is required.
Description : List different starting methods of three phase synchronous motor. Explain any one of them.
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.
asked
May 7, 2020
by
anonymous
Description : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because?
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.
asked
Mar 20, 2018
by
anonymous
Answer :
If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.
asked
Mar 20, 2018
by
anonymous
Description : what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?
Answer :
When excitation of an unloaded salient pole synchronous motor suddenly gets disconnected the motor will stop.
asked
Mar 18, 2018
by
anonymous
Answer :
Slip-rings in a synchronous motor carry direct current.
asked
Mar 20, 2018
by
anonymous
Answer :
The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.
asked
Mar 20, 2018
by
anonymous
Answer :
A synchronous motor running with normal excitation adjusts to load increases essentially by increase in armature current.
asked
Mar 20, 2018
by
anonymous
Answer :
The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.
asked
Mar 20, 2018
by
anonymous
Answer :
A synchronous motor can develop synchronous torque at synchronous speed.
asked
Mar 20, 2018
by
anonymous
Answer :
In a synchronous motor, the armature current has large values for high and low excitation.
Answer :
The size of a synchronous motor decreases with the increase in flux density.
Answer :
The duration of sudden short-circuit test on a synchronous motor is usually about one second.
asked
Mar 20, 2018
by
anonymous
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?
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.
asked
Mar 20, 2018
by
anonymous
Answer :
The construction of a synchronous motor resembles an alternator.
asked
Mar 20, 2018
by
anonymous
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?
asked
Mar 20, 2018
by
anonymous
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.
asked
Mar 20, 2018
by
anonymous
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.
asked
Mar 20, 2018
by
anonymous
Answer :
The armature current of the synchronous motor has large values for low and high excitation.
asked
Mar 20, 2018
by
anonymous
Description : Which motor have more efficiency, synchronous motor or induction motor?
Answer :
Synchronous motor has more efficiency.
asked
Mar 18, 2018
by
anonymous
Description : If we change the excitation of synchronous machine will it affect on motor speed?
Answer :
No, If we change the excitation of synchronous machine it will not affect on motor speed.
asked
Mar 18, 2018
by
anonymous
Description : How can we reverse the direction of rotation of synchronous motor?
Answer :
By reversing supply phase sequence we can reverse the direction of rotation of synchronous motor.
asked
Mar 18, 2018
by
anonymous
Description : What is the maximum value of torque angle in synchronous motor?
Answer :
The maximum value of torque angle in synchronous motor is 90 degrees electrical.
asked
Mar 18, 2018
by
anonymous
Description : If the load of the normally excited synchronous motor is increased the power factor will?
Answer :
If the load of the normally excited synchronous motor is increased the power factor will become lagging.
asked
Mar 18, 2018
by
anonymous
Description : Hunting in synchronous motor cannot be due to?
Answer :
Hunting in synchronous motor cannot be due to windage friction.
asked
Mar 18, 2018
by
anonymous
Description : The synchronous motor which works on leading power factor and does not drive any mechanical load is called?
Answer :
The synchronous motor which works on leading power factor and does not drive any mechanical load is called synchronous condenser.
asked
Mar 18, 2018
by
anonymous
Description : The damping winding in synchronous motor is generally used to?
Answer :
The damping winding in synchronous motor is generally used to provide starting torque and prevent hunting.
asked
Mar 18, 2018
by
anonymous
Description : If the field of synchronous motor is under excited, power factor will be?
Answer :
If the field of synchronous motor is under excited, power factor will be lagging.
asked
Mar 18, 2018
by
anonymous
Description : A synchronous motor can be made self starting by providing?
Answer :
A synchronous motor can be made self-starting by providing damper bar.
asked
Mar 18, 2018
by
anonymous
Description : In a synchronous motor which losses varies with load?
Answer :
In a synchronous motor, copper losses varies with load.
asked
Mar 18, 2018
by
anonymous
Description : The back emf of synchronous motor depends on?
Answer :
The back emf of synchronous motor depends on load angle.
asked
Mar 18, 2018
by
anonymous
Description : Synchronous motor always runs at which speed?
Answer :
Synchronous motor always runs at synchronous speed.
asked
Mar 18, 2018
by
anonymous
Description : Can we use the synchronous motor as the synchronous capacitor?
Answer :
Yes, we can use the synchronous motor as the synchronous capacitor when the synchrnous motor is overexcited.
asked
Mar 18, 2018
by
anonymous
Description : The synchronous motor will develop maximum power when the load angle is?
Answer :
The synchronous motor will develop maximum power when the load angle is 900.
asked
Mar 18, 2018
by
anonymous