# The maximum constant load torque under which a synchronous motor will pull into synchronism...

The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

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.

## Related questions

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?

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.

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.

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.

Description : For a transformer, operating at constant load current, maximum efficiency will occur at?

Answer : For a transformer, operating at constant load current, maximum efficiency will occur at unity power factor.

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

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.

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.

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

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

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.

Answer : In repulsion motor, maximum torque is developed when brush axis is at 45° electrical to the field axis.

Description : Why the speed of synchronous motor is constant?

Answer : For the same H.P. rating and full load speed, following motor has poor starting torque differentially compounded.

Description : 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

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

Description : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?

Answer : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are hysteresis and eddy current losses.

Description : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be

Answer : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be 474 V

Description : 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.

Answer : The effect of increasing load on a synchronous motor running with normal excitation is Increase Ia, but decrease power factor

Description : In synchronous motor, does the winding losses vary with load?

Answer : No, in the synchronous motor the winding losses do not vary with load.

Description : Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.

Answer : The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is 0.5.

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.

Description : 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

Answer : In a self-controlled synchronous motor fed from a variable frequency inverter the frequency of the stator decides the rotor speed

Answer : For constant torque drive armature voltage control speed control method is preferred.

Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is

Answer : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is 150/√3

Answer : Power plant having maximum demand more than the installed rated capacity will have utilisation factor more than unity.

Description : A change of 4% in the supply voltage to an induction motor will produce a change of approximately

Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque

Description : The maximum torque of d.c. motors is limited by?

Answer : The maximum torque of d.c. motors is limited by commutation.

Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.

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

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

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

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.

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.

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

Answer : Three phase synchronous motor will have two sliprings.

Answer : An ideal transformer will have maximum efficiency at a load such that copper loss equal to iron loss.

Description : The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz

Description : Torque angle for the synchronous machine is the angle between (A) stator magnetic field and rotor magnetic field (B) stator magnetic field and net magnetic field in the air gap (C) rotor magnetic field and net magnetic field in the air gap (D) excitation voltage and impedance voltage drop

Answer : Torque angle for the synchronous machine is the angle between rotor magnetic field and net magnetic field in the air gap

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

Answer : Synchronous motor has more efficiency.

Description : Synchronous motor always runs at which speed?

Answer : Synchronous motor always runs at synchronous speed.

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.

Description : In an actual transformer the iron loss remains practically constant from no load to full load because?

Answer : In an actual transformer the iron loss remains practically constant from no load to full load because core flux remains practically constant.

Description : An electric motor in which both stator field and rotor rotates with same speed is called?

Answer : An electric motor in which both stator field and rotor rotates with same speed is called synchronous motor.

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

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.

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

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.

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

← Prev Question Next Question →