Equivalent Circuit MCQ

Test your knowledge with important Equivalent Circuit MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30+ more Equivalent Circuit MCQs on Bissoy. Bissoy App

• If it is desired to approximate the efficiency of an induction motor operating at slip ‘s’, then its efficiency is given by?
  ক

  1-s/1+s

  খ

  1/1+s

  গ

  s/s+1

  ঘ

  s/1-s
• A delta connected capacitance bank is preferred over a star connected bank. This is done to ensure _________
  ক

  lesser capacitance

  খ

  easy calculation

  গ

  easier connection

  ঘ

  all of the mentioned
• A star connected capacitor bank is connected to the induction motor having capacitance C and VA rating as VAs. If the capacitor bank is replaced by a delta bank then?
  ক

  C = C/3, VA = VAs

  খ

  C = 3C, VA = VAs

  গ

  C = C, VA = VAs/3

  ঘ

  C = C/3, VA = VAs/3
• Induction generators will deliver power at _________
  ক

  leading p.f.

  খ

  lagging p.f.

  গ

  unity p.f.

  ঘ

  zero p.f.
• A 3-phase induction machine is running at super synchronous speed. For the machine to be self excited it _________
  ক

  draws reactive power from mains

  খ

  draws real power from mains

  গ

  feeds reactive power to mains

  ঘ

  generates emf by gradual voltage build up
• In a 3-phase induction generator which is self excited, load has been increased. To keep the frequency of the generated voltage constant, speed of the induction machine should be _________
  ক

  increased

  খ

  decreased

  গ

  maintained less than rated synchronous speed

  ঘ

  maintained more than rated synchronous speed
• At standstill the equivalent of the 3-phase induction motor is similar to _________
  ক

  short-circuited two winding transformer

  খ

  open circuit two winding transformer

  গ

  stand still synchronous motor

  ঘ

  none of the mentioned
• The leakage reactance and the rotor resistance are constant throughout the operation in an induction motor.
  ক

  True

  খ

  False
• The leakage reactances are less than their values at the full load operating conditions. Why?
  ক

  Due to large inrush current during starting

  খ

  Due to very low saturation

  গ

  Due to speed is not same as synchronous speed

  ঘ

  All of the mentioned
• The actual rotor resistance referred to the stator if the induction motor is?
  ক

  r2

  খ

  (r2)/s

  গ

  (r2)/(1-s)

  ঘ

  (r2)*(1-s)/s
• The electrical anlogous of the mechanical load in the induction machine is given by?
  ক

  (r2)*(1-s)/s

  খ

  (r2)

  গ

  (r2)/s

  ঘ

  (r2)/(1-s)
• Rc in the below circuit represents?
  ক

  core loss of induction motor

  খ

  no load losses of induction motor

  গ

  iron losses of induction motor

  ঘ

  copper losses of induction motor