Question is ⇒ A rotory converter can also be run as a, Options are ⇒ (A) d.c. shunt motor, (B) d.c. series motor, (C) d.c. compound motor, (D) induction motor, (E) synchronous motor, Leave your comments or Download question paper.

Question is ⇒ A rotory converter can also be run as a, Options are ⇒ (A) d.c. shunt motor, (B) d.c. series motor, (C) d.c. compound motor, (D) induction motor, (E) synchronous motor, Leave your comments or Download question paper. Previous question Next question


Q1.	A rotory converter can also be run as a
A.	d.c. shunt motor [Wrong Answer]
B.	d.c. series motor [Wrong Answer]
C.	d.c. compound motor [Wrong Answer]
D.	induction motor [Wrong Answer]
E.	synchronous motor [Correct Answer]
View Answer 8 -3 Explanation:- Answer : E Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

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Also Read Similar Questions Below :

⇒ A synchronous motor can be made selfstarting by providing
damper winding on rotor poles
damper winding on stator
damper winding on stator as well as rotor poles
none of the above

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

⇒ Synchronous motors are
not-self starting
self-starting
essentially self-starting
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

⇒ In a synchronous motor, damper windings are provided on
stator frame
rotor shaft
pole faces
none of the above

⇒ In a synchronous motor, the armature current has large values for
high excitation only
low excitation only
both high and low excitation
none of the above

⇒ The speed of a synchronous motor
increases as the load increases
decreases as the load decreases
always remains constant
none of the above

⇒ The power factor of a synchronous motor is better than that of induction motor because
stator supply is relieved of responsibility of producing magnetic field
mechanical load on the motor can be adjusted
synchronous motor runs at synchronous speed
synchronous motor has large air gap

⇒ Synchronous motors are generally not self-starting because
the direction of rotation is not fixed
the direction of instantaneous torque reverses after half cycle
startes cannot be used on these machines
starting winding is not provided on the machines

⇒ In a synchronous motor which loss varies with load ?
Windage loss
Bearing friction loss
Copper loss
Core loss

⇒ VVhen the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop
inductor motor torque
induction generator torque
synchronous motor torque
d.c. motor toque

⇒ If the field of a synchronous motor is under-excited, the power factor will be
zero
unity
lagging
leading

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

⇒ 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
the stator current will be very small
the stator current will be very high
the back e.m.f. will be more than the supply voltage

⇒ When V is the supply voltage and R is the rotor resistance per phase, the mechanical power developed by the synchronous motor will be proportional to

V²

R²

⇒ An over-excited synchronous motor takes
leading current
lagging current
both (a) and (b)
none of the above

⇒ 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

⇒ If in a synchronous motor, driving a given mechanical load and drawing current at a leading power factor from constant voltage supply its field excitation is increased, its power factor
will become more
will become less
will remain unchanged
none of the above

⇒ An important advantage of a synchronous motor over wound round induction motor is that
its power factor may be varied at will
its speed is independent of supply frequency
its speed may be controlled more easily
none of the above

⇒ Which of the following motors will be used in electric clocks ?
D.C. shunt motor
D.C. series motor
A.C. induction motor
A.C. synchronous motor

⇒ A synchronous motor is running with normal excitation. When the load is increased, the armature current drawn by it increases because
speed of the motor is reduced
power factor is decreased
Eb (back e.m.f.) becomes less than V (applied voltage)
Er (net resultant voltage) in armature is increased

⇒ By which of the following methods the constant speed of a synchronous motor can be changed to new fixed value ?
By changing the supply frequency
By interchanging any two phases
By changing the applied voltage
By changing the load.

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

⇒ The power developed by a synchronous motor will be maximum when the load angle is
zero
45°
90°
120°

⇒ In a synchronous motor it the back e.m.f. generated in the armature at noload is approximately equal to the applied voltage, then
the motor is said to be fully loaded
the torque generated is maximum
the excitation is said to be zero per cent
the excitation is said to be hundred per cent

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

⇒ In a synchronous motor, the breakdown torque is
directly proportional to applied voltage
directly proportional to the square of the applied voltage
inversely proportional to applied voltage
none of the above

⇒ The operating speed of a synchtunous motor can be changed to new fixed value by
changing the load
changing the supply voltage
changing frequency
using brakes

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

⇒ In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on
d.c. excitation only
speed of the motor
load on the motor
both the speed and rotor flux