Question is ⇒ The maximum power developed in a synchronous motor occurs at a coupling angle of, Options are ⇒ (A) 30°, (B) 60°, (C) 90°, (D) 180°, (E) , Leave your comments or Download question paper.

Question is ⇒ The maximum power developed in a synchronous motor occurs at a coupling angle of, Options are ⇒ (A) 30°, (B) 60°, (C) 90°, (D) 180°, (E) , Leave your comments or Download question paper. Previous question Next question


Q1.	The maximum power developed in a synchronous motor occurs at a coupling angle of
A.	30° [Wrong Answer]
B.	60° [Wrong Answer]
C.	90° [Correct Answer]
D.	180° [Wrong Answer]
View Answer 5 -3 Explanation:- Answer : C Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

Previous question Next question

Also Read Similar Questions Below :

⇒ Power factor of a synchronous motor is unity when
the armature current is maximum
the armature current is minimum
the armature current is zero
none of the above

⇒ Which of the following motors is nonself starting ?
D.C. series motor
synchronous motor
Squirrel cage induction motor
Wound round induction motor

⇒ The minimum armature current of the synchronous motor corresponds to operation at
zero power factor leading
unity power factor
0.707 power factor lagging
0.707 power factor leading

⇒ The ratio of starting torque to running torque in a synchronous motor is
zero
one
two
infinity

⇒ If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will
stop
run as induction motor
function as static condenser
burn with dense smoke

⇒ The speed of the synchronous motor
increases with increase in load
decreases as load increases
varies with power factor
always remains constant

⇒ The armature current of the synchronous motor has higher values for
high excitation only
low excitation only
both (a) and (b)
none of the above

⇒ The induced e.m.f. in a synchronous motor working on leading power factor will be
more than the supply voltage
less than the supply voltage
equal to the supply voltage

⇒ A synchronous motor is running on a load with normal excitation. Now if the load on the motor is increased
power factor as well as armature current will decrease
power factor as well as armature current will increase
power factor will increase but armature current will decrease
power factor will decrease and armature current will increase

⇒ The maximum power developed in a synchronous motor will depend on
the rotor excitation only
the supply voltage only
the rotor excitation and supply voltage both
the rotor excitation, supply voltage and maximum value of coupling angle (90°)

⇒ The speed regulation of a synchronous motor is always
0.01
0.005
positive
zero

⇒ When the excitation of an unloaded salient pole synchronous motor suddenly gets disconnected
the motor stops
it runs as a reluctance motor at the same speed
it runs as a reluctance motor at a lower speed
none of the above

⇒ A synchronous motor will always stop when
supply voltage fluctuates
load in motor varies
excitation winding gets disconnected
supply voltage frequency changes

⇒ Which of the following methods is used to start a synchronous motor ?
Damper winding
Star-delta starter
Damper winding in conjunction with star-delta starter
Resistance starter in the armature circuit

⇒ A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because
synchronous motor has no slip
stator supply is not required to produce magnetic field
mechanical load on the rotor remains constant
synchronous motor has large airgap

⇒ A synchronous motor can develop synchronous torque
when under loaded
while over-excited
only at synchronous speed
below or above synchronous speed

⇒ The construction of a synchronous motor resembles
a series motor
an induction motor
an alternator
a rotary converter

⇒ The maximum value of torque that a synchronous motor can develop without losing its synchronism is known as
slip torque
pull-out torque
breaking torque
synchronising torque

⇒ In a synchronous motor, the forced vibrations will be maximum when driving
a reciprocating air compressor
a centrifugal pump
a centrifugal blower
any of the above

⇒ If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then
it runs at a slower speed
the motor stops
it continues to run at the same speed
it runs at a very high speed

⇒ The standard full-load power factor ratings for synchronous motors are
zero or 0.8 leading
unity or 0.8 lagging
unity or 0.8 leading
unity or zero

⇒ A 3-phase synchronous motor is running clockwise. If the direction of its field current is reversed
the motor will stop
the motor continue to run in the same direction
the winding of the motor will burn
the motor will run in the reverse direction

⇒ In which of the following motors the stator and rotor fields rotate simultaneously ?
D.C. motor
Reluctance motor
Universal motor
Synchronous motor

⇒ In a synchronous motor, V-curves represent relation between
armature current and field current
power factor and speed
field current and speed
field current and power factor

⇒ A rotory converter can also be run as a
d.c. shunt motor
d.c. series motor
d.c. compound motor
induction motor

⇒ As the load is applied to a synchronous motor, the motor takes more armature current because
the increased load has to take more current
the rotor by shifting its phase backward causes motor to take more current
the back e.m.f. decreases causing ah increase in motor current
the rotor strengthens the rotating field casuing more motor current

⇒ A synchronous motor connected to infinite bus-bars has at constant full load, 100% excitation and unity power factor. On changing the excitation only, the armature current will have
no change of power factor
lagging power factor with over-excitation
leading power factor with underexcitiltion
leading power factor vvith over-excitation

⇒ When a 3-phase synchionous generator is supplying a zero power factor lagging load, the armature field affects the main field in the following way
augments it directly
directly opposes it
cross-magnetises it
none of the above

⇒ The angle between the rotor poles and stator poles, in a synchronous motor, is known as
power factor angle
torque angle
synchronizing angle
angle of retardation

⇒ Slip-rings in a synchronous motor carry
direct current
alternating current
no current
all of the above