GETCO Exam Paper (22-07-2015) In the standard B-H curve X axis and Y axis intercepts respctively represents residual magnetism and coercive force coercive force and residual magnetism Flux and MMF Hysteresis loss and Flux residual magnetism and coercive force coercive force and residual magnetism Flux and MMF Hysteresis loss and Flux ANSWER DOWNLOAD EXAMIANS APP
GETCO Exam Paper (22-07-2015) The PU impedance of a 1089 MVA, 33 kV generator is 1, the ohmic value of its impedance is: 1 0.5 10 100 1 0.5 10 100 ANSWER DOWNLOAD EXAMIANS APP
GETCO Exam Paper (22-07-2015) The breaking capacity of a CB is usually expressed interms of volts MW amperes MVA volts MW amperes MVA ANSWER DOWNLOAD EXAMIANS APP
GETCO Exam Paper (22-07-2015) A transformer has negative voltage regulation when its load PF is lagging unity zero leading lagging unity zero 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) In synchronous motor, V-curve is a graph of Armature current Vs power factor Armature current Vs active power Armature current Vs reactive power Armature current Vs Field current Armature current Vs power factor Armature current Vs active power Armature current Vs reactive power Armature current Vs Field current ANSWER EXPLANATION DOWNLOAD EXAMIANS APP v curve: armature current → field currentInverted V curve: power factor → field current
GETCO Exam Paper (22-07-2015) For eliminating 7th harmonics from generated EMF in alternator the fractional pitch must be 2\3 6\7 7\8 5\6 2\3 6\7 7\8 5\6 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP fractional pitch = Cos( α/2)α is obtain from: (nα/2)=90˚ where n is harmonicα=25.7143˚fractional pitch=6/7
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