Electrical Machines If the applied voltage to a dc machine is 230 V, then the back emf, for maximum power developed, is 115 V 200 V 230 V 460 V 115 V 200 V 230 V 460 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC compound motor can be reversed by interchanging armature or field connections. armature connections. shunt field connections. series field connections. armature or field connections. armature connections. shunt field connections. series field connections. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main purpose of providing tertiary winding in a three phase transformer is to interconnect three voltage systems. to suppress harmonic and unbalance in voltage. to carry extra load. None of these to interconnect three voltage systems. to suppress harmonic and unbalance in voltage. to carry extra load. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, the armature reaction results in demagnetization of centers of poles. demagnetization of leading & magnetization of trailing pole tip. magnetization of inter poles. magnetization of leading and demagnetization of trailing pole tip. demagnetization of centers of poles. demagnetization of leading & magnetization of trailing pole tip. magnetization of inter poles. magnetization of leading and demagnetization of trailing pole tip. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum efficiency will occur, when copper loss is_______to iron loss? less than any of the above equal to greater than less than any of the above equal to greater than ANSWER DOWNLOAD EXAMIANS APP
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