Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.
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.
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.
Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.
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.
Description : Why the speed of synchronous motor is constant?
Description : The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?
Last Answer : Ns equals f/pair pole 50/4 - 12.5
Last Answer : An alternator coupled to a hydraulic turbine runs at slow speed, as compared to others.
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 : 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.
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?
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 : 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.
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 : 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.
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.