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) In the equivalent circuit of a double cage induction motor, the two rotor cages can be considered
A) to be in parallel
B) to be in series-parallel
C) to be in series
D) to be in parallel with stator
Ans:A
2) The advantage of the double squirrel cage induction motor over single cage rotor is that its
A) efficiency is higher
B) power factor is higher
C) slip is larger
D) starting current is lower
Ans:D
3) In a double squirrel cage induction motor, the resistance of upper cage is................that of inner cage
A) equal to
B) 4 to 5 times of
C) one-fourth of
D) none of these
Ans:B
4) The deep-bar rotors or double cage rotors are employed to
A) increase starting torque
B) improve efficiency
C) increase pull out torque
D) reduce rotor core loss
Ans:A
5) During starting of a double cage induction motor, the current induced in the rotor
A) flows mostly through the lower cage
B) flows mostly through the upper cage
C) is equally divided between the two windings
D) none of the above
Ans:B
6) Squirrel cage induction motors have the advantages of
A) cheaper in initial as well as in maintenance cost
B) nearly constant speed, high overload capacity, simple starting arrangement and high power factor
C) lower copper losses and high operation efficiency
D) all of the above
Ans:D
7) Squirrel cage induction motor have the disadvantages of
A) higher starting current and poor starting torque
B) higher sensitivity to fluctuations in supply voltage and low power factor at light-load
C) no possibility of speed regulation
D) all of the above
Ans:D
8) Slip-ring induction motors have the advantages of
A) high starting torque and high overload capacity
B) nearly constant speed
C) low starting current in comparison to squirrel cage induction motor
D) all of the above
Ans:D
9) Slip-ring motors have the disadvantage of
A) low efficiency and low power factor in comparison to squirrel cage induction motors
B) low power factor at light load
C) sensitivity to fluctuations in supply voltage
D) all of the above
Ans:D
10) For high starting torque, the most suitable 3-phase induction motor is ................ induction motor
A) slip ring
B) squirrel cage
C) double cage
D) deep bar squirrel cage
Ans:A
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1) In the equivalent circuit of a double cage induction motor, the two rotor cages can be considered
A) to be in parallel
B) to be in series-parallel
C) to be in series
D) to be in parallel with stator
Ans:A
2) The advantage of the double squirrel cage induction motor over single cage rotor is that its
A) efficiency is higher
B) power factor is higher
C) slip is larger
D) starting current is lower
Ans:D
3) In a double squirrel cage induction motor, the resistance of upper cage is................that of inner cage
A) equal to
B) 4 to 5 times of
C) one-fourth of
D) none of these
Ans:B
4) The deep-bar rotors or double cage rotors are employed to
A) increase starting torque
B) improve efficiency
C) increase pull out torque
D) reduce rotor core loss
Ans:A
5) During starting of a double cage induction motor, the current induced in the rotor
A) flows mostly through the lower cage
B) flows mostly through the upper cage
C) is equally divided between the two windings
D) none of the above
Ans:B
6) Squirrel cage induction motors have the advantages of
A) cheaper in initial as well as in maintenance cost
B) nearly constant speed, high overload capacity, simple starting arrangement and high power factor
C) lower copper losses and high operation efficiency
D) all of the above
Ans:D
7) Squirrel cage induction motor have the disadvantages of
A) higher starting current and poor starting torque
B) higher sensitivity to fluctuations in supply voltage and low power factor at light-load
C) no possibility of speed regulation
D) all of the above
Ans:D
8) Slip-ring induction motors have the advantages of
A) high starting torque and high overload capacity
B) nearly constant speed
C) low starting current in comparison to squirrel cage induction motor
D) all of the above
Ans:D
9) Slip-ring motors have the disadvantage of
A) low efficiency and low power factor in comparison to squirrel cage induction motors
B) low power factor at light load
C) sensitivity to fluctuations in supply voltage
D) all of the above
Ans:D
10) For high starting torque, the most suitable 3-phase induction motor is ................ induction motor
A) slip ring
B) squirrel cage
C) double cage
D) deep bar squirrel cage
Ans:A
If you like my post share it with your friends and subscribe for latest updates..
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