Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of supply voltage. Change of supply frequency. Change of rotor resistance. Change of number of pole. Change of supply voltage. Change of supply frequency. Change of rotor resistance. Change of number of pole. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When pure inductive load is connected to the alternator, what is the effect of armature reaction? Cross magnetization None of these Demagnetization Magnetization Cross magnetization None of these Demagnetization Magnetization ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1000 1200 1203 1080 1000 1200 1203 1080 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of rotation of 5th harmonic component in the stator of an induction motor is (1 / 5) times the synchronous speed. 5 times the synchronous speed. 0.5 times the synchronous speed. (1 / 15) times the synchronous speed. (1 / 5) times the synchronous speed. 5 times the synchronous speed. 0.5 times the synchronous speed. (1 / 15) times the synchronous speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 60% 68% 40% 38% 60% 68% 40% 38% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronising power of a synchronous motor varies All of these directly as Xs2 directly as synchronous reactances Xs inversely as 1/Xs All of these directly as Xs2 directly as synchronous reactances Xs inversely as 1/Xs ANSWER DOWNLOAD EXAMIANS APP
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