GETCO Exam Paper (22-07-2015) In rotating electrical machines, the insulation temperature limit for class B type is 130˚C 150˚C 105˚C 180˚C 130˚C 150˚C 105˚C 180˚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 breaking method save energy? resistor breaking dynamic breaking plugging regenerative breaking resistor breaking dynamic breaking plugging regenerative breaking ANSWER EXPLANATION DOWNLOAD EXAMIANS APP three types of electric breaking:Regenerative breaking( leads to economic and energy consevation)pugging (more efficient method of breaking)rheostatic breaking
GETCO Exam Paper (22-07-2015) Slip at maximum torque depends on rotor resistance and reactance stator resistance load current stator reactance rotor resistance and reactance stator resistance load current stator reactance ANSWER EXPLANATION DOWNLOAD EXAMIANS APP at maximum torque:S=R₂/X₂
GETCO Exam Paper (22-07-2015) For formation of the Y bus matrix (using node voltage analysis) in power system network modelling _____ is used Faraday's law all are correct KCL KVL Faraday's law all are correct KCL KVL 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) For selecting low voltage cable which of the following factors is not important? short circuit current rating permissible voltage drop voltage grade current carrying capacity short circuit current rating permissible voltage drop voltage grade current carrying capacity ANSWER DOWNLOAD EXAMIANS APP
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