Electrical Machines In a synchronous motor, damper windings are provided on None of these pole faces. stator frame. rotor shaft. None of these pole faces. stator frame. rotor shaft. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Lamination of transformer core is made of silicon steel. cast iron. cast steel. wrought iron. silicon steel. cast iron. cast steel. wrought iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the cause of rapid brush wear may be any of above. imperfect contact. severe sparking. rough commutator surface. any of above. imperfect contact. severe sparking. rough commutator surface. 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 : 1, 2 and 4 2, 3 and 4 1 and 3 1, 2, and 3 1, 2 and 4 2, 3 and 4 1 and 3 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that both Eb and Td are zero Eb is unchanged, but Td is zero both Eb and Td are unchanged Eb is zero, but Td is unchanged both Eb and Td are zero Eb is unchanged, but Td is zero both Eb and Td are unchanged Eb is zero, but Td is unchanged ANSWER DOWNLOAD EXAMIANS APP
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