Hi friends, this post is about induction motor objectives. These are some of the questions asked in previous question papers of Gate, IES and other competitive exams. check out and comment if you have any doubts....
1) A Squirrel Cage induction motor is not favored when.......................is the main consideration
A) initial cost
B) maintenance cost
C) high starting torque
D) higher efficiency and higher power factor
Ans:C
2) A slip ring induction motor is recommended for applications requiring
A) high starting torque
B) variable speed operation
C) frequent starting, stopping and reversing operations
D) all of the above features
Ans:D
3) Which of the following ac motor is widely used?
A) Squirrel Cage induction motor
B) Slip-ring induction motor
C) Double cage induction motor
D) Synchronous motor
Ans:A
4) Induction motors, Over synchronous motors, have the advantages of
A) being self starting
B) having no requirement for dc excitation
C) possibility of speed control to small extent
D) simplicity and lower cost
E) all of the above
Ans:E
5) Unbalanced 3-phase voltage supply to an induction motor causes excessive heating of
A) rotor
B) stator
C) rotor shaft
D) none of these
Ans:A
6) Unbalanced supply voltage given to a 3-phase, delta connected induction motor will cause
A) zero sequence currents
B) less heating of motor
C) negative sequence component current
D) all the above
Ans:C
7) Single phase preventer
A) suppresses negative sequence component currents
B) compensates for voltage drops
C) provides protection in the event of non-availability of one of the phases
D) none of the above
Ans:C
8) Increase in supply voltage to a 3-phase induction motor will not cause
A) decrease in input current and so reduction in copper losses
B) increase in torque
C) decrease in speed as well as in core loss
D) operating temperature abnormally higher owing to increase in core loss
Ans:C
9) Decrease in supply voltage to a 3-phase induction motor will not cause
A) any difficulty in accelerating the load
B) increase in torque
C) decrease in speed as well as in core loss
D) increase in stator as well as rotor currents
E) operating temperature abnormally high owing to increase in core loss
Ans:B
10) A 3-phase induction motor is operating at its rated torque. If the supply voltage falls to 75% of its normal value
A) the motor will get heated up to inadmissible extent after some time
B) the motor will stop
C) the slip will decrease
D) the stator and rotor current will decrease
Ans:A
These are some of the objectives of induction machines.. If you like my post share it with your friends and subscribe for latest updates..
1) A Squirrel Cage induction motor is not favored when.......................is the main consideration
A) initial cost
B) maintenance cost
C) high starting torque
D) higher efficiency and higher power factor
Ans:C
2) A slip ring induction motor is recommended for applications requiring
A) high starting torque
B) variable speed operation
C) frequent starting, stopping and reversing operations
D) all of the above features
Ans:D
3) Which of the following ac motor is widely used?
A) Squirrel Cage induction motor
B) Slip-ring induction motor
C) Double cage induction motor
D) Synchronous motor
Ans:A
4) Induction motors, Over synchronous motors, have the advantages of
A) being self starting
B) having no requirement for dc excitation
C) possibility of speed control to small extent
D) simplicity and lower cost
E) all of the above
Ans:E
5) Unbalanced 3-phase voltage supply to an induction motor causes excessive heating of
A) rotor
B) stator
C) rotor shaft
D) none of these
Ans:A
6) Unbalanced supply voltage given to a 3-phase, delta connected induction motor will cause
A) zero sequence currents
B) less heating of motor
C) negative sequence component current
D) all the above
Ans:C
7) Single phase preventer
A) suppresses negative sequence component currents
B) compensates for voltage drops
C) provides protection in the event of non-availability of one of the phases
D) none of the above
Ans:C
8) Increase in supply voltage to a 3-phase induction motor will not cause
A) decrease in input current and so reduction in copper losses
B) increase in torque
C) decrease in speed as well as in core loss
D) operating temperature abnormally higher owing to increase in core loss
Ans:C
9) Decrease in supply voltage to a 3-phase induction motor will not cause
A) any difficulty in accelerating the load
B) increase in torque
C) decrease in speed as well as in core loss
D) increase in stator as well as rotor currents
E) operating temperature abnormally high owing to increase in core loss
Ans:B
10) A 3-phase induction motor is operating at its rated torque. If the supply voltage falls to 75% of its normal value
A) the motor will get heated up to inadmissible extent after some time
B) the motor will stop
C) the slip will decrease
D) the stator and rotor current will decrease
Ans:A
These are some of the objectives of induction machines.. If you like my post share it with your friends and subscribe for latest updates..
EmoticonEmoticon