Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.443. 0.573. 0.512. 0.649. 0.443. 0.573. 0.512. 0.649. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor winding for a 3-phase slip-ring induction motor having delta-connected stator must be connected in None of these delta. star. delta or star according to need. None of these delta. star. delta or star according to need. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of a alternator, if P = number of poles and N = revolution made per second? 120P / N Hz. PN / 2 Hz. 120 / PN Hz. 120N / P Hz. 120P / N Hz. PN / 2 Hz. 120 / PN Hz. 120N / P Hz. 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% 68% 40% 60% 38% 68% 40% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 100 KVA transformer is operating at 60 Hz, 240 V supply. The same transformer is operating at 50 Hz, 200 V supply. The new rating is 83.33 KVA 100 KVA 123.3 KVA 50 KVA 83.33 KVA 100 KVA 123.3 KVA 50 KVA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature All of these They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature All of these ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS