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?

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1 Answer

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.

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Related questions

What is the maximum value of torque angle in 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.

The synchronous motor will develop maximum power when the load angle is?

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.

If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then?

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.

A synchronous motor can develop synchronous torque?

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

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

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

A synchronous motor running with normal excitation adjusts to load increases essentially by increase in?

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

The coupling angle or load angle of synchronous motor is defined as the angle between the?

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.

If the load of the normally excited synchronous motor is increased the power factor will?

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.

The synchronous motor which works on leading power factor and does not drive any mechanical load is called?

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.

In a synchronous motor which losses varies with load?

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

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

In repulsion motor, maximum torque is developed when?

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

For the same H.P. rating and full load speed, following motor has poor starting torque?

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

A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s.

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

Last 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

The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and

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

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The effect of increasing load on a synchronous motor running with normal excitation is

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.

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

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

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

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

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

In a self-controlled synchronous motor fed from a variable frequency inverter

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

Last Answer : 2

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

Last 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.

For constant torque drive which speed control method is preferred ?

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

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

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

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

Torque angle for the synchronous machine is the angle between

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

If the field of synchronous motor is under excited, power factor will be?

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.

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

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

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

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

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

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

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control

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Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases 

Slip-rings in a synchronous motor carry?

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

The efficiency of a properly designed synchronous motor will usually fall in range?

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

A synchronous motor has better power factor as compared to that of an equivalent induction motor...

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.

The operating speed of a synchronous motor can be changed to new fixed value by?

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

In case one phase of a three-phase synchronous motor is short-circuited the motor will?

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

In a synchronous motor, the armature current has large values for?

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

The size of a synchronous motor decreases with the increase in?

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

The duration of sudden short-circuit test on a synchronous motor is usually about?

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

The construction of a synchronous motor resembles?

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

If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will?

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

The armature current of the synchronous motor?

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

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

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

Last Answer : Synchronous motor has more efficiency.

If we change the excitation of synchronous machine will it affect on motor speed?

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.

How can we reverse the direction of rotation of synchronous motor?

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.

Hunting in synchronous motor cannot be due to?

Description : Hunting in synchronous motor cannot be due to?

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

The damping winding in synchronous motor is generally used to?

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.

An unexcited single phase synchronous motor is ?

Description : An unexcited single phase synchronous motor is ?

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

A synchronous motor can be made self starting by providing?

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.

The back emf of synchronous motor depends on?

Description : The back emf of synchronous motor depends on?

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

Synchronous motor always runs at which speed?

Description : Synchronous motor always runs at which speed?

Last Answer : Synchronous motor always runs at synchronous speed.

Can we use the synchronous motor as the synchronous capacitor?

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.

what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?

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.

Three phase synchronous motor will have how many sliprings?

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

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