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.
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.
Last Answer : Slip-rings in a synchronous motor carry direct current.
Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.
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.
Last Answer : A synchronous motor running with normal excitation adjusts to load increases essentially by increase in armature current.
Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.
Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.
Last Answer : In case one phase of a three-phase synchronous motor is short-circuited the motor will not start.
Last Answer : In a synchronous motor, the armature current has large values for high and low excitation.
Last Answer : The size of a synchronous motor decreases with the increase in flux density.
Last Answer : The duration of sudden short-circuit test on a synchronous motor is usually about one second.
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.
Last Answer : The construction of a synchronous motor resembles an alternator.
Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.
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.
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.
Last Answer : The armature current of the synchronous motor has large values for low and high excitation.
Description : Which motor have more efficiency, synchronous motor or induction motor?
Last Answer : Synchronous motor has more efficiency.
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.
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.
Description : Hunting in synchronous motor cannot be due to?
Last Answer : Hunting in synchronous motor cannot be due to windage friction.
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.
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.
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.
Description : An unexcited single phase synchronous motor is ?
Last Answer : An unexcited single-phase synchronous motor is reluctance motor.
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.
Description : In a synchronous motor which losses varies with load?
Last Answer : In a synchronous motor, copper losses varies with load.
Description : The back emf of synchronous motor depends on?
Last Answer : The back emf of synchronous motor depends on load angle.
Description : Synchronous motor always runs at which speed?
Last Answer : Synchronous motor always runs at synchronous speed.
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.
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.
Description : Three phase synchronous motor will have how many sliprings?
Last Answer : Three phase synchronous motor will have two sliprings.
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.
Description : Why is a capacitor used in a single phase motor and not in three phase motor ?
Last 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.
Description : Explain the working of a single phase capacitor start induction motor.
Last Answer : Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc
Last Answer : If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then Electrolytic capacitor will, in all probability, suffer break down.
Last Answer : Two-value capacitor motor finds increased application as compressor motor in small home air-conditioners because it has low starting as well as running currents at relatively high power factor.
Last Answer : In a ceiling fan employing capacitor run motor secondary winding surrounds the primary winding.
Last Answer : In a two value capacitor motor, the capacitor used for running purposes is paper spaced oil filled type.
Last Answer : In a capacitor start single-phase motor, when capacitor is replaced by a resistance motor will continue to run in same direction.
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?
Last 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.
Last Answer : The value of starting capacitor of a fractional horse power motor will be 300 uF .
Last Answer : In a capacitor start motor, the phase displacement between starting and running winding can be nearly 90°.
Last Answer : If the capacitor of a single-phase motor is short-circuited the motor will not start.
Last Answer : Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.
Description : 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.
Description : 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.
Description : 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
Description : Damper winding in a synchronous motor
Last Answer : Damper winding in a synchronous motor Serves to start the motor.