Hi friends, this post is about objectives of synchronous machine. Mcq's on synchronous machines which are asked recently in various competitive exams like Gate , Upsc exams and so on. check out and comment if you have any doubts regarding this bits..
1) The stator core stampings also have openings which make.....................
A) axial
B) radial
C) axial as well as radial
D) none of the above
Ans:C
2) The open slots are more commonly used in the stator of a synchronous machines as
A) the inductance of the winding is less
B) they permit the placement of form wound and insulated coils giving least expensive and more satisfactory
C) both (a) and (b)
D) none of these
Ans:C
3) The field system of an alternator is usually excited at
A) 1250/250 V dc
B) 110/220 V ac
C) 3-phase 50 Hz, 400 V
D) 230 V ac
Ans:A
4) The slip-rings employed in a 3-phase synchronous machine are insulated for
A) output rated voltage
B) low voltage
C) very low voltage
D) very high voltage
Ans:B
5) In a large synchronous generator, the damper windings is provided for
A) absorption of energy of oscillations when operating in parallel with another alternator
B) suppression of spontaneous hunting when supplying power to a transmission line with high resistance/reactance ratio
C) providing a low resistance path for the currents due to unbalancing of voltages
D) all of the above
Ans:D
6) Squirrel cage bars placed in the rotor pole faces of an alternator help reducing hunting
A) above synchronous speed only
B) below synchronous speed only
C) above and below synchronous speeds both
D) none of the above
Ans:C
7) Hydro-generators are generally employed to run at .................. rpm
A) 500
B) 1000
C) 1500
D) 3000
Ans:A
8) In case of turbo-alternators, rotor is made of
A) forged steel
B) cast iron
C) stainless steel
D) manganese steel
E) laminated silicon steel
Ans:A
9) The salient pole rotors have
A) two or four projecting poles carrying field coils
B) a large number of projecting poles carrying the field coils
C) thick steel lamination s riveted together and fixed to the rotor by a dove-tail joint
D) pole faces usually provided with slots for damping windings
E) all of the above expect (a)
Ans:E
10) In salient pole field structure, the pole shoes cover about ................ of pole pitch
A) one-third
B) one half
C) two-third
D) whole
Ans:C
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1) The stator core stampings also have openings which make.....................
A) axial
B) radial
C) axial as well as radial
D) none of the above
Ans:C
2) The open slots are more commonly used in the stator of a synchronous machines as
A) the inductance of the winding is less
B) they permit the placement of form wound and insulated coils giving least expensive and more satisfactory
C) both (a) and (b)
D) none of these
Ans:C
3) The field system of an alternator is usually excited at
A) 1250/250 V dc
B) 110/220 V ac
C) 3-phase 50 Hz, 400 V
D) 230 V ac
Ans:A
4) The slip-rings employed in a 3-phase synchronous machine are insulated for
A) output rated voltage
B) low voltage
C) very low voltage
D) very high voltage
Ans:B
5) In a large synchronous generator, the damper windings is provided for
A) absorption of energy of oscillations when operating in parallel with another alternator
B) suppression of spontaneous hunting when supplying power to a transmission line with high resistance/reactance ratio
C) providing a low resistance path for the currents due to unbalancing of voltages
D) all of the above
Ans:D
6) Squirrel cage bars placed in the rotor pole faces of an alternator help reducing hunting
A) above synchronous speed only
B) below synchronous speed only
C) above and below synchronous speeds both
D) none of the above
Ans:C
7) Hydro-generators are generally employed to run at .................. rpm
A) 500
B) 1000
C) 1500
D) 3000
Ans:A
8) In case of turbo-alternators, rotor is made of
A) forged steel
B) cast iron
C) stainless steel
D) manganese steel
E) laminated silicon steel
Ans:A
9) The salient pole rotors have
A) two or four projecting poles carrying field coils
B) a large number of projecting poles carrying the field coils
C) thick steel lamination s riveted together and fixed to the rotor by a dove-tail joint
D) pole faces usually provided with slots for damping windings
E) all of the above expect (a)
Ans:E
10) In salient pole field structure, the pole shoes cover about ................ of pole pitch
A) one-third
B) one half
C) two-third
D) whole
Ans:C
If you like my post please share it with your friends and subscribe to latest updates.. If you have doubts you can start new topic on forum and start discussion with our readers..
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