flux density remains unaffected
iron losses are reduced
core flux density is reduced
core flux density is increased
Answer is Right!
Answer is Wrong!
Detailed SolutionWhen a given transformer is run at its rated voltage but reduced frequency, its
Transformers
32. Which of the following property is not necessarily desirable in the material for transformer core?
Mechanical strength
Low hysteresis loss
High thermal conductivity
High permeability
Answer is Right!
Answer is Wrong!
33. The ‘crawling’ in an induction motor is caused by
high loads
low voltage supply
improper design of machine
harmonics developed in the motor
Answer is Right!
Answer is Wrong!
Detailed SolutionThe ‘crawling’ in an induction motor is caused by
34. The term ‘cogging’ is associated with
three phase transformers
compound generators
series motors
induction motors
Answer is Right!
Answer is Wrong!
35. Short circuit test on transformers is conducted to determine
hysteresis losses
copper losses
core losses
eddy current losses
Answer is Right!
Answer is Wrong!
Detailed SolutionShort circuit test on transformers is conducted to determine
36. When the equivalent circuit diagram of doouble squirrelcage induction motor is constructed the two cages can be considered
in series
in parallel
in series-parallel
in parallel with stator
Answer is Right!
Answer is Wrong!
37. An ideal transformer is one which has
no losses and magnetic leakage
interleaved primary and secondary windings
a common core for its primary and secondary windings
core of stainless steel and winding of pure copper metal
Answer is Right!
Answer is Wrong!
38. Which of the following is the main advantage of an auto-transformer over a two winding transformer?
Hysteresis losses are reduced
Saving in winding material
Copper losses are negligible
Eddy losses are totally eliminated
Answer is Right!
Answer is Wrong!
39. While conducting short-circuit test on a transformer the following side is short circuited
High voltage side
Low voltage side
Primary side
Secondary side
Answer is Right!
Answer is Wrong!
40. Helical coils can be used on
low voltage side of high kVA transformers
high frequency transformers
high voltage side of small capacity transformers
high voltage side of high kVA rating transformers
Answer is Right!
Answer is Wrong!