Electrical Machines A generator may loose residual magnetism due to vibrations. over excitation. any of these. heating. vibrations. over excitation. any of these. heating. 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 material used for commutator brushes is mostly carbon. copper. cast iron. mica. carbon. copper. cast iron. mica. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in dc motor results short circuit. increase in speed. decrease in speed. open circuit. short circuit. increase in speed. decrease in speed. open circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In auto transformer if the turn ratio is K, what is the power transferred inductively? K × input power (1-K) × input power both A and B None of these K × input power (1-K) × input power both A and B None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A crusher is equipped with DC shunt motor. Reluctance motor. Synchronous motor. Slip ring induction motor. DC shunt motor. Reluctance motor. Synchronous motor. Slip ring induction motor. ANSWER DOWNLOAD EXAMIANS APP