Transformers Objectives Part 05

81 . A tap changer is used on a transformer for adjustments in secondary voltage

82 . Over currents in a transformer affects insulation life, temperature rise and mechanical stress

83 . In a transformer the tapings are usually provided on high voltage side

84 . A current transformer used the instruments like ammeter, Wattmeter and Watt hour meter

85 . Voltage transformer of 0.1 class of accuracy is used

86 . Three transformer each of the single phase type sets will be costly

87 . Commutator is not fitting on the transformer

88 . The reactance of a transformer depends on the leakage flux

89 . If the frequency of the supply voltage is double eddy current loss will increase

90 . No load current in a transformer as a percentage of full load current is 1% to 3%

91 . In a transformer maximum voltage regulation occurs when the power factor of the load is lagging

92 . The regulation of a good transformer should be near 1%

93 . In a step up transformer the f2/f1 has value one

94 . In a transformer minimum voltage regulation occurs when the power factor of the load is leading

95 . Scott connections are used to three phase to three phase and three phase to two phase transformation

96 . In Scott connections the neutral point divides the teaser winding in the ratio 1:2

97 . In a large capacity transformer 5% of the turns at the ends of high voltage winding are provided with extra insulation to provide protection due to surges occurring during switching operations

98 . The permittivity of Bakelite is approximately 4.4

99 . The permittivity of transformer oil is about 2.2

100 . Buchholz relay is used in transformer protection