Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? They are self lubricating in nature All of these In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature All of these In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve with fall of terminal voltage. deteriorate with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with rise in terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with rise in terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In the 3-phase induction motor, the resultant flux is of a constant nature and is 3 times maximum value of flux due to any phase 3/2 times maximum value of flux due to any phase 1/2 times maximum value of flux due to any phase equal to φm, where φm is the maximum flux due to any phase 3 times maximum value of flux due to any phase 3/2 times maximum value of flux due to any phase 1/2 times maximum value of flux due to any phase equal to φm, where φm is the maximum flux due to any phase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 8-pole, DC generator has a simplex wave-wound armature containing 32 coils of 6 turns each. Its flux per pole is 0.06 Wb. The machine is running at 250 rpm. The induced armature voltage is 384 V 192 V 96 V 768 V 384 V 192 V 96 V 768 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For an ideal transformer the winding should have minimum resistance on primary side and maximum resistance on secondary side maximum resistance on primary side and least resistance on secondary side no ohmic resistance on either side equal resistance on primary and secondary side minimum resistance on primary side and maximum resistance on secondary side maximum resistance on primary side and least resistance on secondary side no ohmic resistance on either side equal resistance on primary and secondary side 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
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