[amp_mcq option1=”voltage device” option2=”current device” option3=”power device” option4=”main flux device” correct=”option1″]
Transformers
42. The value of flux involved m the e.m.f. equation of a transformer is
[amp_mcq option1=”average value” option2=”r.m.s. value” option3=”maximum value” option4=”instantaneous value” correct=”option4″]
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
[amp_mcq option1=”3000 kVA” option2=”1000 kVA” option3=”500 kVA” option4=”250 kVA” correct=”option3″]
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
[amp_mcq option1=”Zero” option2=”1 ohm” option3=”1000 ohms” option4=”Infinity” correct=”option4″]
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
[amp_mcq option1=”copper loss becomes high in proportion to the output” option2=”iron loss is increased considerably” option3=”voltage drop both in primary and secondary becomes large” option4=”secondary output is much less as compared to primary input” correct=”option1″]
Detailed SolutionThe efficiency of a transformer, under heavy loads, is comparatively low because
46. The leakage flux in a transformer depends upon
[amp_mcq option1=”load current” option2=”load current and voltage” option3=”load current, voltage and frequency” option4=”load current, voltage, frequency and power factor” correct=”option1″]
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
[amp_mcq option1=”same efficiency” option2=”same polarity” option3=”same kVA rating” option4=”same number of turns on the secondary side.” correct=”option3″]
48. Natural air cooling is generally restricted for transformers up to
[amp_mcq option1=”1.5 MVA” option2=”5 MVA” option3=”15 MVA” option4=”50 MVA” correct=”option1″]
Detailed SolutionNatural air cooling is generally restricted for transformers up to
49. The transformer oil should have _____ volatility and _____ viscosity.
[amp_mcq option1=”low,low” option2=”high,high” option3=”low,high” option4=”high,low” correct=”option3″]
Detailed SolutionThe transformer oil should have _____ volatility and _____ viscosity.
50. In the transformer following winding has got more cross-sectional area
[amp_mcq option1=”Low voltage winding” option2=”High voltage winding” option3=”Primary winding” option4=”Secondary winding” correct=”option2″]
Detailed SolutionIn the transformer following winding has got more cross-sectional area