Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called crawling. harmonics. resonance. cogging. crawling. harmonics. resonance. cogging. 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? 40% 68% 38% 60% 40% 68% 38% 60% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following DC motors has got maximum relieving property? Cummulative compound. Series. Shunt. Differentical compound. Cummulative compound. Series. Shunt. Differentical compound. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sequence of induction motor is RYB, then the direction of induction motor can be changed by which of the following sequence? BYR RBY BRY All of these BYR RBY BRY All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to reduce both eddy current and hysteresis loss. increase the permeability. reduce eddy current loss only. reduce hysteresis loss only. reduce both eddy current and hysteresis loss. increase the permeability. reduce eddy current loss only. reduce hysteresis loss only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % ANSWER DOWNLOAD EXAMIANS APP