GETCO Exam Paper (22-07-2015) A transformer has negative voltage regulation when its load PF is unity zero lagging leading unity zero lagging leading ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Voltage regulation = ((no load voltage)-(full load voltage)/(no load voltage))VR at leading PF = ((I*R*cosφ)-(I*X*sinφ))/VVR at lagging PF = ((I*R*cosφ)+(I*X*sinφ))/V
GETCO Exam Paper (22-07-2015) Two watt meter method for 3 phase circuit is preferred over other methods because it can be used for star or delta connected load all are correct PF of the load can also be estimated it can be used for balanced or unbalanced load it can be used for star or delta connected load all are correct PF of the load can also be estimated it can be used for balanced or unbalanced load ANSWER DOWNLOAD EXAMIANS APP
GETCO Exam Paper (22-07-2015) Critical clearing time of a fault in a power system is related to Reactive power limit Transient stability limit Short circuit limit Steady state limit Reactive power limit Transient stability limit Short circuit limit Steady state limit ANSWER DOWNLOAD EXAMIANS APP
GETCO Exam Paper (22-07-2015) Stray loss is equal to _____ field copper loss & iron loss copper loss and iron loss mechanical loss & iron loss frictional loss & copper loss field copper loss & iron loss copper loss and iron loss mechanical loss & iron loss frictional loss & copper loss ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Answer in official key is “mechanical loss & iron loss ”.Many times stray loss is also considered as total loss actually accured minus calculatable loss. This means loss that can be calculated is known as stray loss.
GETCO Exam Paper (22-07-2015) In rotating electrical machines, the insulation temperature limit for class B type is 150˚C 180˚C 130˚C 105˚C 150˚C 180˚C 130˚C 105˚C ANSWER EXPLANATION DOWNLOAD EXAMIANS APP insulation Class and temperature limit(in ˚C) is given below:Y - 90A- 105E- 120B-130F-155H-180C- above 180
GETCO Exam Paper (22-07-2015) Which of the following is not function of substation batteries? operating automatic control circuits operating protective relay systems provide supply to the excitation system emergency lighting circuits operating automatic control circuits operating protective relay systems provide supply to the excitation system emergency lighting circuits ANSWER DOWNLOAD EXAMIANS APP
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