Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to zero. None of above. Back emf is equal to applied voltage. Back emf is equal to half the applied voltage. Back emf is equal to zero. None of above. Back emf is equal to applied voltage. Back emf is equal to half the applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to reduce chance of crawling. reduce chance of cogging. reduce magnetizing current. increase starting torque. reduce chance of crawling. reduce chance of cogging. reduce magnetizing current. increase starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction effect is more in which of the following methods? None of these armature resistance control field weakening method same in both methods None of these armature resistance control field weakening method same in both methods ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main disadvantage(s) of the ward-Leonard system is/are high maintenance cost. all of above. poor overall efficiency. high initial cost. high maintenance cost. all of above. poor overall efficiency. high initial cost. 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% 38% 40% 68% 60% 38% 40% 68% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In alternator, the rotary part is none of these. armature. core. magnetic field poles. none of these. armature. core. magnetic field poles. ANSWER DOWNLOAD EXAMIANS APP
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