Hi friends, this is another post on induction motor objectives check out and comment here...
1) The direction of rotor current produced in an induction motor can be determined by
A) Lenz's law
B) induction law
C) Fleming's right hand rule
D) Fleming's left hand rule
Ans:C
2) In a slip ring induction motor, the frequency of rotor currents can be measured with a
A) galvanometer
B) wattmeter
C) dc moving coil millivoltmeter
D) none of the above
Ans:C
3) In an induction motor under running condition, the rotor reactance per phase is ............its standstill phase reactance
A) s times
B) equal to
C) 1/s times
D) (1-s) times
Ans:A
4) In an induction motor the phase reactance is ................... in comparison to phase resistance
A) quite high
B) very small
C) slightly high
D) almost same
Ans:A
5) The frequency of rotor currents at stand still is equal to
A) zero
B) 2f
C) f
D) sf
Ans:C
6) A 3-phase induction motor is operating at slip s. If its two supply leads are interchanged, then its slip at that instant will be
A) 2-s
B) 2+s
C) 1+s
D) 1-s
Ans:A
7) The speed of rotating field due to rotor currents relative to rotor surface in an induction motor is
A) Ns
B) sNs
C) N
D) sN
Ans:B
8) An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50 Hz, the emf in the rotor will have a frequency of
A) 1.5 Hz
B) 48.5 Hz
C) 5.15 Hz
D) 75 Hz
Ans:A
9) A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50 Hz. The slip of the motor is
A) 2%
B) 4%
C) 5%
D) 25 %
Ans:B
10) In a 3-phase induction motor reactance under running condition is less than its standstill value. This is due to reduction in
A) rotor inductance
B) stator magnetic flux
C) frequency of rotor emf
D) mutual flux linking the stator and rotor
Ans:C
If you like this post please share it with your friends and comment here if you have any doubts..
1) The direction of rotor current produced in an induction motor can be determined by
A) Lenz's law
B) induction law
C) Fleming's right hand rule
D) Fleming's left hand rule
Ans:C
2) In a slip ring induction motor, the frequency of rotor currents can be measured with a
A) galvanometer
B) wattmeter
C) dc moving coil millivoltmeter
D) none of the above
Ans:C
3) In an induction motor under running condition, the rotor reactance per phase is ............its standstill phase reactance
A) s times
B) equal to
C) 1/s times
D) (1-s) times
Ans:A
4) In an induction motor the phase reactance is ................... in comparison to phase resistance
A) quite high
B) very small
C) slightly high
D) almost same
Ans:A
5) The frequency of rotor currents at stand still is equal to
A) zero
B) 2f
C) f
D) sf
Ans:C
6) A 3-phase induction motor is operating at slip s. If its two supply leads are interchanged, then its slip at that instant will be
A) 2-s
B) 2+s
C) 1+s
D) 1-s
Ans:A
7) The speed of rotating field due to rotor currents relative to rotor surface in an induction motor is
A) Ns
B) sNs
C) N
D) sN
Ans:B
8) An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50 Hz, the emf in the rotor will have a frequency of
A) 1.5 Hz
B) 48.5 Hz
C) 5.15 Hz
D) 75 Hz
Ans:A
9) A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50 Hz. The slip of the motor is
A) 2%
B) 4%
C) 5%
D) 25 %
Ans:B
10) In a 3-phase induction motor reactance under running condition is less than its standstill value. This is due to reduction in
A) rotor inductance
B) stator magnetic flux
C) frequency of rotor emf
D) mutual flux linking the stator and rotor
Ans:C
If you like this post please share it with your friends and comment here if you have any doubts..
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