voltage device
current device
power device
main flux device
Answer is Right!
Answer is Wrong!
Transformers
42. The value of flux involved m the e.m.f. equation of a transformer is
average value
r.m.s. value
maximum value
instantaneous value
Answer is Right!
Answer is Wrong!
Detailed SolutionThe value of flux involved m the e.m.f. equation of a transformer is
43. Natural oil cooling is used for transformers up to a rating of
3000 kVA
1000 kVA
500 kVA
250 kVA
Answer is Right!
Answer is Wrong!
Detailed SolutionNatural oil cooling is used for transformers up to a rating of
44. In a transformer the resistance between its primary and secondary should be
Zero
1 ohm
1000 ohms
Infinity
Answer is Right!
Answer is Wrong!
Detailed SolutionIn a transformer the resistance between its primary and secondary should be
45. The efficiency of a transformer, under heavy loads, is comparatively low because
copper loss becomes high in proportion to the output
iron loss is increased considerably
voltage drop both in primary and secondary becomes large
secondary output is much less as compared to primary input
Answer is Right!
Answer is Wrong!
Detailed SolutionThe efficiency of a transformer, under heavy loads, is comparatively low because
46. The leakage flux in a transformer depends upon
load current
load current and voltage
load current, voltage and frequency
load current, voltage, frequency and power factor
Answer is Right!
Answer is Wrong!
Detailed SolutionThe leakage flux in a transformer depends upon
47. For the parallel operation of single phase transformers it is necessary that they should have
same efficiency
same polarity
same kVA rating
same number of turns on the secondary side.
Answer is Right!
Answer is Wrong!
48. Natural air cooling is generally restricted for transformers up to
1.5 MVA
5 MVA
15 MVA
50 MVA
Answer is Right!
Answer is Wrong!
Detailed SolutionNatural air cooling is generally restricted for transformers up to
49. The transformer oil should have _____ volatility and _____ viscosity.
low,low
high,high
low,high
high,low
Answer is Right!
Answer is Wrong!
Detailed SolutionThe transformer oil should have _____ volatility and _____ viscosity.
50. In the transformer following winding has got more cross-sectional area
Low voltage winding
High voltage winding
Primary winding
Secondary winding
Answer is Right!
Answer is Wrong!
Detailed SolutionIn the transformer following winding has got more cross-sectional area