Transformer cores are laminated in order to A simplify its construction B minimize eddy current loss C reduce cost D reduce hysterisis loss
3235A transformer has negative voltage regulation when its load PF is A zero B unity C lagging D leading
1 8096Essential condition for parallel operation of two single phase transformer is that they should have same A polarity B kVA rating C voltage ratio D % impedance
1 11257Saving in copper achieved by converting a 2 winding transformer in to an auto transformer is determined by A voltage transformation ratio B load on secondary C quality of core material D size of transformer core
3055kVA rating of ordinary transformer is increased when connected as an auto transformer because A transformation ratio increased B secondary voltage increased C energy is transferred both inductively and conductively D secondary current increased
2601At light load transformer efficiency is less because A secondary output is low B transformer losses are high C fixed loss is high compared to output D copper loss is small
1 5759Which of the following connection is best suited for 3-ph, 4 wire system A delta-delta B star-star C delta-star D star-delta
2 9893A T-T transformer can not be parallel with transformer A V-V B star-delta C star-star D delta-delta
1 6445Following test should be conducted to find out relative polarity of transformenr terminals A no load test B back to back test C phasing out test D none of above
2178In power transformer tappings are provided on A high voltage side B low voltage side C In middle of both the windings D both high and low voltage side
NNN,
2 5290Main advantage of auto transformer over two windings transformer is that A it needs no cooling B it uses only one winding C core losses are reduced D it has simple construction
2899Material commonly used in making transformer core is A cast iron B mild steel C high silicom steel D high carbon steel
1 3468If we impress a dc voltage of 230 V on an unloaded 230 V, 50 Hz transformer it wi A give high secondary voltage B burn out C give secondary voltage as per K D none of these
1962If we impress a dc voltage of 230 V on an unloaded 230 V, 50 Hz transformer it wi A give high secondary voltage B burn out C give secondary voltage as per K D none of these
1 3187Short circuit voltage of a transformer mainly depend on A ohmic resistance of primary B ohmic resistance of secondary C magnitude of leakage flux D cross sectional area of core
1 9529Post New Electrical Engineering Questions
pls someone send me sample question papers along with the key.thanks in advance
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