Description : What is the difference between synchronous and asynchronous generator?
asked
Mar 15, 2018
by
anonymous
Description : What is the difference between synchronous and asynchronous motors?
Answer :
The motor which rotates at constant speed is called synchronous motor. And that constant speed is called as synchronous speed. And the motor which does not rotates at constant speed are called asynchronous motor. Asynchronous motor is also called as Induction motor.
asked
Mar 15, 2018
by
anonymous
Description : Compare characteristics of asynchronous and synchronous transmission mode (four points).
Answer :
Synchronous transmission Asynchronous transmission 1. Synchronous transmission are synchronized by an external clock. 1. Asynchronous transmission are synchronized by special signals along the transmission ... for transferring a small amount of data as it is simple and economical.
asked
Aug 4, 2019
by
anonymous
Description : Compare synchronous and asynchronous counter.
Answer :
Asynchronous Counter Synchronous Counter In an Asynchronous Counter the output of one Flip Flop acts as the clock Input of the next Flip Flop. In a Synchronous Counter all the Flip Flop's are ... Also called as serial counter Also called as Parallel Counter
asked
Jul 31, 2019
by
anonymous
Description : Compare Asynchronous sequential and synchronous sequential circuits.
Answer :
SR. NO. ASYNCHRONOUS SEQUENTIAL CIRCUIT SYNCHRONOUS SEQUENTIAL CIRCUITS. 1 Output can be changed at any instant of time by changing the input Output changes at discrete ... the counter change state simultaneously. This is because all the flip-flops are clocked simultaneously.
asked
Jul 21, 2019
by
anonymous
Description : Synchronous vs asynchronous logic
Answer :
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asked
Jul 6, 2019
by
anonymous
Description : Asynchronous circuits are usually faster than synchronous circuits because
Answer :
Asynchronous circuits are usually faster than synchronous circuits because they are free running and do not depend on the frequency of the clock
asked
Apr 26, 2018
by
anonymous
Answer :
Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.
asked
Mar 20, 2018
by
anonymous
Description : What is the principle of synchronous motor?
asked
Mar 15, 2018
by
anonymous
Description : What is the use of synchronous motor?
asked
Mar 15, 2018
by
anonymous
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
asked
Apr 28, 2018
by
anonymous
Description : A three-phase synchronous motor connected to ac mains is running at full load and unity power factor. lf its shaft load is reduced by half and field current is held constant then its new power factor will be
Answer :
Leading
asked
Apr 28, 2018
by
anonymous
Description : Damper winding in a synchronous motor
Answer :
Damper winding in a synchronous motor Serves to start the motor.
asked
May 8, 2018
by
anonymous
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
asked
Apr 28, 2018
by
anonymous
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.
asked
Mar 20, 2018
by
anonymous
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.
asked
Mar 20, 2018
by
anonymous
Description : Why synchronous motor Cannot start itself?
asked
Mar 15, 2018
by
anonymous
Description : How can we improve power factor using synchronous motor?
asked
Mar 15, 2018
by
anonymous
Description : Why the speed of synchronous motor is constant?
asked
Mar 15, 2018
by
anonymous
Answer :
Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.
asked
Mar 6, 2018
by
anonymous
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.
asked
Mar 3, 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
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 : 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
Description : What is back EMF of synchronous motor?
asked
Mar 15, 2018
by
anonymous
Description : Draw and explain V and inverted V curves for synchronous motor.
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.
asked
May 7, 2020
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
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 : 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 : List different torques in synchronous motor.
Answer :
Different Torques in Synchronous Motor: 1) Starting torque 2) Running torque 3) Pull-in torque 4) Pull-out torque
asked
May 7, 2020
by
anonymous
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
asked
Apr 29, 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
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 :
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 case one phase of a three-phase synchronous motor is short-circuited the motor will not start.
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
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 : 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 armature current of the synchronous motor has large values for low and high excitation.
asked
Mar 20, 2018
by
anonymous
Answer :
An over excited synchronous motor on noload is known as synchronous condenser.
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