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 most appropriate operating speeds in rpm of generators used in Thermal,Nuclear and Hydro power plants would respectively be
A) 3000, 300 and 1500
B) 3000, 3000 and 300
C) 1500, 1500 and 3000
D) 1000, 900 and 750
Ans:B
2) The aircraft alternators are designed to generate emf of high frequency of 400 Hz in order to
A) reduce the bulk
B) compensate for high speeds
C) make the systems free from external disturbances
D) all of the above
Ans:A
3) Armature winding is one in which
A) emf is induced by the leakage flux
B) emf is induced by the main or working flux
C) working or main flux is created by the field current
D) working or main flux is created by the armature current
Ans:B
4) Armature winding in ac machines
A) is always closed one
B) is always open one
C) may be either closed one giving delta connections or open one giving star connections
Ans:C
5) The stator of modern alternators are wound for ...................... phase groups
A) 180°
B) 120°
C) 60°
D) 240°
Ans:C
6) Concentrated winding has
A) one coil per phase
B) two coils per phase
C) one coil per pair of poles per phase
D) one coil side per pole pair per phase
Ans:C
7) For a two layer winding the number of stator slots is equal to the number of
A) poles
B) conductors
C) coil sides
D) coils
Ans:D
8) For a concentrated winding the polar group of each phase is ..................... electrical degrees apart
A) 360
B) 180
C) 120
D) 60
Ans:A
9) Distributed winding is preferred over concentrated winding as it
A) reduces noise
B) reduces the machine size
C) reduces the amount of copper required
D) improves the generated emf waveform and adds rigidity and mechanical strength to the winding
Ans:D
10) In a synchronous alternator, which of the following coils will have emf closer to sine wave form?
A) Concentrated winding in full pitch coils
B) Concentrated winding in short pitch coils
C) Distributed winding in full pitch coils
D) Distributed winding in short pitch coils
Ans:D
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..
1) The most appropriate operating speeds in rpm of generators used in Thermal,Nuclear and Hydro power plants would respectively be
A) 3000, 300 and 1500
B) 3000, 3000 and 300
C) 1500, 1500 and 3000
D) 1000, 900 and 750
Ans:B
2) The aircraft alternators are designed to generate emf of high frequency of 400 Hz in order to
A) reduce the bulk
B) compensate for high speeds
C) make the systems free from external disturbances
D) all of the above
Ans:A
3) Armature winding is one in which
A) emf is induced by the leakage flux
B) emf is induced by the main or working flux
C) working or main flux is created by the field current
D) working or main flux is created by the armature current
Ans:B
4) Armature winding in ac machines
A) is always closed one
B) is always open one
C) may be either closed one giving delta connections or open one giving star connections
Ans:C
5) The stator of modern alternators are wound for ...................... phase groups
A) 180°
B) 120°
C) 60°
D) 240°
Ans:C
6) Concentrated winding has
A) one coil per phase
B) two coils per phase
C) one coil per pair of poles per phase
D) one coil side per pole pair per phase
Ans:C
7) For a two layer winding the number of stator slots is equal to the number of
A) poles
B) conductors
C) coil sides
D) coils
Ans:D
8) For a concentrated winding the polar group of each phase is ..................... electrical degrees apart
A) 360
B) 180
C) 120
D) 60
Ans:A
9) Distributed winding is preferred over concentrated winding as it
A) reduces noise
B) reduces the machine size
C) reduces the amount of copper required
D) improves the generated emf waveform and adds rigidity and mechanical strength to the winding
Ans:D
10) In a synchronous alternator, which of the following coils will have emf closer to sine wave form?
A) Concentrated winding in full pitch coils
B) Concentrated winding in short pitch coils
C) Distributed winding in full pitch coils
D) Distributed winding in short pitch coils
Ans:D
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..
EmoticonEmoticon