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What is back EMF of synchronous motor?
asked
Mar 15, 2018
by
anonymous
What is back EMF of synchronous motor?
back
emf
synchronous
motor
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asked
Mar 18, 2018
by
anonymous
The back emf of synchronous motor depends on?
The back emf of synchronous motor depends on?
Last answer:
The back emf of synchronous motor depends on load angle.
back
emf
synchronous
motor
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answer
asked
Mar 15, 2018
by
anonymous
What is the back EMF of a dc motor?
What is the back EMF of a dc motor?
back
emf
dc
motor
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asked
Mar 15, 2018
by
anonymous
What is the back EMF of the motor?
What is the back EMF of the motor?
back
emf
motor
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answers
asked
Mar 20, 2018
by
anonymous
What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?
Last answer:
The armature may burn if the back e.m.f. of a D.C. motor vanishes suddenly.
back
emf
dc
motor
vanishes
suddenly
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answer
asked
Mar 20, 2018
by
anonymous
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.
mechanical
power
shunt
motor
maximum
ratio
back
emf
voltage
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answer
asked
Apr 27, 2020
by
anonymous
What is back emf?
What is back emf?
Last answer:
Back EMF: When a current carrying conductor is placed in a magnetic field it experiences a force; when it moves due to the force it (conductor) cuts the magnetic field due to which an emf is ... (hence the applied armature voltage) is opposed by the induced emf which is therefore called as Back emf.
what
is
back
emf
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asked
Mar 15, 2018
by
anonymous
What is back EMF in inductor?
What is back EMF in inductor?
back
emf
inductor
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0
answers
asked
Mar 15, 2018
by
anonymous
What is the back EMF in Transformers?
What is the back EMF in Transformers?
back
emf
transformers
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0
answers
asked
Mar 15, 2018
by
anonymous
What is the back EMF?
What is the back EMF?
Last answer:
When the armature of a d.c. motor rotates under the influence of the driving torque, the armature conductors move through the magnetic field and hence e.m.f. is induced in them as in a generator. The ... that energy conversion in a d.c. motor is only possible due to the production of back emf.
back
emf
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1
answer
asked
Mar 15, 2018
by
anonymous
Do AC induction motors have back EMF?
Do AC induction motors have back EMF?
ac
induction
motors
back
emf
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answers
asked
Mar 20, 2018
by
anonymous
In case of D.C. shunt motors the speed is dependent on back e.m.f. only because?
Last answer:
In case of D.C. shunt motors the speed is dependent on back e.m.f. only because flux is practically constant in D:C. shunt motors.
dc
shunt
motors
speed
back
emf
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1
answer
asked
Mar 18, 2018
by
anonymous
What is the maximum value of torque angle in synchronous motor?
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.
maximum
torque
angle
synchronous
motor
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1
answer
asked
Mar 15, 2018
by
anonymous
What is the principle of synchronous motor?
What is the principle of synchronous motor?
principle
synchronous
motor
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answers
asked
Mar 15, 2018
by
anonymous
What is the use of synchronous motor?
What is the use of synchronous motor?
use
synchronous
motor
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answers
asked
Aug 6, 2017
by
anonymous
what is the difference between synchronous and asynchronous motor?
what is the difference between synchronous and asynchronous motor?
Last answer:
Asynchronous motors and syncrouns motor are called as dc machines. and also syncrouns motor called as induction motor. Asynonymous motor as are rotates with constant speed we not able to operate . ... It is able to operate. These are a small difference between syncrouns and asynchronous motors.
synchronous
asynchronous
motor
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2
answers
asked
Mar 20, 2018
by
anonymous
Centrifugal switch disconnects the auxiliary winding of the motor at about what percent of synchronous speed?
Last answer:
Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.
centrifugal
switch
disconnects
auxiliary
winding
motor
synchronous
speed
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1
answer
asked
Mar 18, 2018
by
anonymous
what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?
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.
excitation
unloaded
salient
pole
synchronous
motor
disconnected
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1
answer
asked
Dec 31, 2017
by
anonymous
The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?
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
induction
motor
synchronous
speed
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2
answers
asked
Apr 28, 2018
by
anonymous
The effect of increasing load on a synchronous motor running with normal excitation is
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.
Last answer:
The effect of increasing load on a synchronous motor running with normal excitation is Increase Ia, but decrease power factor
effect
load
synchronous
motor
running
normal
excitation
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1
answer
asked
Mar 20, 2018
by
anonymous
In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will?
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.
reluctance
motor
synchronous
speed
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87
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1
answer
asked
Mar 20, 2018
by
anonymous
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.
one
phase
three-phase
synchronous
motor
short-circuited
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173
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1
answer
asked
Mar 20, 2018
by
anonymous
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.
short-circuit
test
synchronous
motor
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113
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1
answer
asked
Mar 20, 2018
by
anonymous
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.
field
winding
unloaded
salient
pole
synchronous
motor
open
circuited
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116
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1
answer
asked
Mar 20, 2018
by
anonymous
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.
coupling
angle
load
synchronous
motor
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135
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1
answer
asked
Mar 18, 2018
by
anonymous
If the load of the normally excited synchronous motor is increased the power factor will?
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.
load
normally
excited
synchronous
motor
increased
power
factor
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1
answer
asked
Mar 18, 2018
by
anonymous
If the field of synchronous motor is under excited, power factor will be?
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.
field
synchronous
motor
excited
power
factor
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151
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1
answer
asked
Mar 15, 2018
by
anonymous
Why the speed of synchronous motor is constant?
Why the speed of synchronous motor is constant?
speed
synchronous
motor
constant
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53
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0
answers
asked
Apr 28, 2018
by
anonymous
A three-phase synchronous motor connected to ac mains is running at full load and unity power factor.
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
Last answer:
Leading
synchronous
motor
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455
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2
answers
asked
Mar 20, 2018
by
anonymous
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.
synchronous
motor
synchronised
supply
running
load
negligible
loss
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87
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1
answer
asked
Mar 20, 2018
by
anonymous
An over excited synchronous motor on noload is known as?
Last answer:
An over excited synchronous motor on noload is known as synchronous condenser.
over
excited
synchronous
motor
noload
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55
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1
answer
asked
Mar 18, 2018
by
anonymous
The synchronous motor which works on leading power factor and does not drive any mechanical load is called?
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.
synchronous
motor
leading
power
factor
drive
mechanical
load
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69
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1
answer
asked
Mar 18, 2018
by
anonymous
The damping winding in synchronous motor is generally used to?
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.
damping
winding
synchronous
motor
used
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119
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1
answer
asked
Mar 18, 2018
by
anonymous
An unexcited single phase synchronous motor is ?
An unexcited single phase synchronous motor is ?
Last answer:
An unexcited single-phase synchronous motor is reluctance motor.
unexcited
single
phase
synchronous
motor
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1
answer
asked
Mar 18, 2018
by
anonymous
The synchronous motor will develop maximum power when the load angle is?
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.
synchronous
motor
develop
maximum
power
load
angle
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1
answer
asked
May 7, 2020
by
anonymous
List different starting methods of three phase synchronous motor. Explain any one of them.
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.
list
different
starting
methods
of
three
phase
synchronous
motor
explain
any
one
them
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1
answer
asked
Apr 28, 2018
by
anonymous
The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and
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
Last 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
maximum
reluctance
power
salient-pole
synchronous
motor
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71
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1
answer
asked
Mar 20, 2018
by
anonymous
If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in?
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.
synchronous
speed
motor
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69
views
1
answer
asked
Mar 20, 2018
by
anonymous
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%.
efficiency
designed
synchronous
motor
usually
range
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55
views
1
answer
asked
Mar 20, 2018
by
anonymous
A synchronous motor has better power factor as compared to that of an equivalent induction motor...
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.
synchronous
power
factor
equivalent
induction
motor
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86
views
1
answer
asked
Mar 20, 2018
by
anonymous
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.
operating
speed
synchronous
motor
fixed
value
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83
views
1
answer
asked
Mar 20, 2018
by
anonymous
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.
size
synchronous
motor
decreases
increase
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133
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1
answer
asked
Mar 20, 2018
by
anonymous
The construction of a synchronous motor resembles?
Last answer:
The construction of a synchronous motor resembles an alternator.
construction
synchronous
motor
resembles
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1
answer
asked
Mar 20, 2018
by
anonymous
The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor...
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?
maximum
torque
synchronous
motor
rated
stator
supply
voltage
frequency
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0
answers
asked
Mar 20, 2018
by
anonymous
The armature current of the synchronous motor?
Last answer:
The armature current of the synchronous motor has large values for low and high excitation.
armature
current
synchronous
motor
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67
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1
answer
asked
Mar 18, 2018
by
anonymous
If we change the excitation of synchronous machine will it affect on motor speed?
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.
change
excitation
synchronous
machine
affect
motor
speed
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68
views
1
answer
asked
Mar 18, 2018
by
anonymous
How can we reverse the direction of rotation of synchronous motor?
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.
reverse
direction
rotation
synchronous
motor
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185
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1
answer
asked
Mar 6, 2018
by
anonymous
Can we make power factor of synchronous motor leading by adjusting its excitation?
Last answer:
Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.
power
factor
synchronous
motor
leading
adjusting
excitation
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83
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1
answer
asked
May 7, 2020
by
anonymous
Draw and explain V and inverted V curves for synchronous motor.
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.
draw
and
explain
v
inverted
curves
for
synchronous
motor
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156
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1
answer
asked
May 7, 2020
by
anonymous
List different torques in synchronous motor.
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
list
different
torques
in
synchronous
motor
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49
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1
answer
asked
May 8, 2018
by
anonymous
Damper winding in a synchronous motor
Damper winding in a synchronous motor
Last answer:
Damper winding in a synchronous motor Serves to start the motor.
damper
winding
synchronous
motor
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1
answer
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