Electrical Machines If the field current is reduced to zero the maximum power developed by alternator is 1.644 KW. 5.46 KW. 2.73 KW. 0.9103 KW. 1.644 KW. 5.46 KW. 2.73 KW. 0.9103 KW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machines have highest power factor with respect to magnetizing current? Closed slot type machines. Any of the above. Open slot type machines. Semi closed slot type machine. Closed slot type machines. Any of the above. Open slot type machines. Semi closed slot type machine. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer, the frequency of a voltage at the secondary is any of the above. equal to primary. less than primary. greater than the primary. any of the above. equal to primary. less than primary. greater than the primary. 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% 68% 38% 40% 60% 68% 38% 40% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A simple method of increasing the voltage of a DC generator is to increase the number of turns in field coil. increase the number of turns in armature coil. increase the source frequency. increase the speed of shaft rotation. increase the number of turns in field coil. increase the number of turns in armature coil. increase the source frequency. increase the speed of shaft rotation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 78.5% 67.5% 72.5% 82.5% 78.5% 67.5% 72.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
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