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Synchronous motors
| 1-Dont try to cram or spend more time here just read it fast and cover syllabus then practice MCQ's cheptor of same topic to check your progress. . |
| 2-Wrong options are also given but dont concentrate there, Right answer is in bold format. |
| Q1 ⇒ Mostly, synchronous motors are of salient pole type machines [other wrong options] [Discuss in forum] |
| Q2 ⇒ For V-curves for a synchronous motor
the graph is drawn between field current and armature current [other wrong options] [Discuss in forum] |
| Q3 ⇒ The percentage slip in case of a synchronous
motor is zero [other wrong options] [Discuss in forum] |
| Q4 ⇒ Synchronsizing power of a synchronous
machine is inversely proportional to the synchronous reactance [other wrong options] [Discuss in forum] |
| Q5 ⇒ The speed of the synchronous motor always remains constant [other wrong options] [Discuss in forum] |
| Q6 ⇒ Which of the following methods is used
to start a synchronous motor ? Damper winding in conjunction with star-delta starter [other wrong options] [Discuss in forum] |
| Q7 ⇒ A synchronous motor installed at the
receiving end substation operates with
such an excitation that it takes power
at lagging power factor. Now if the applied
voltage of the synchronous motor
goes down, the power factor of the
synchronous motor will improve [other wrong options] [Discuss in forum] |
| Q8 ⇒ If one-phase of a 3-phase synchronous
motor is short-circuited, motor will refuse to start [other wrong options] [Discuss in forum] |
| Q9 ⇒ In a 3-phase synchronous motor, the
negative phase sequence exists when
the motor is supplied with unbalanced voltage [other wrong options] [Discuss in forum] |
| Q10 ⇒ The torque angle, in a synchronous
motor, is the angle between the rotating stator flux and rotor poles [other wrong options] [Discuss in forum] |
| Q11 ⇒ Which of the following losses is not
dissipated by tile stator core surface in
a synchronous motor ? Windage losses [other wrong options] [Discuss in forum] |
| Q12 ⇒ The coupling angle or load angle of
synchronous motor is defined as the angle between the rotor and the stator poles of opposite polarity [other wrong options] [Discuss in forum] |
| Q13 ⇒ In a synchronous motor, the forced
vibrations will be maximum when driving a reciprocating air compressor [other wrong options] [Discuss in forum] |
| Q14 ⇒ A synchronous motor can be started by any of the above [other wrong options] [Discuss in forum] |
| Q15 ⇒ The synchronous motor is not inherently
self-starting because the force required to accelerate the rotor to the synchronous speed in an instant is absent [other wrong options] [Discuss in forum] |
| Q16 ⇒ The back e.m.f. of a synchronous motor
depends on load angle [other wrong options] [Discuss in forum] |
| Q17 ⇒ The operating speed of a synchtunous
motor can be changed to new fixed
value by changing frequency [other wrong options] [Discuss in forum] |
| Q18 ⇒ Synchronous motors are not-self starting [other wrong options] [Discuss in forum] |
| Q19 ⇒ Dust and dirt accumulation on motor
winding will result in rise in winding temperature [other wrong options] [Discuss in forum] |
| Q20 ⇒ VVhen the rotor speed, in a synchronous
machine, becomes more than the synchronous
speed during hunting, the
damper bars develop induction generator torque [other wrong options] [Discuss in forum] |
| Or |