Electrical Machines What is/are the advantages of parallel operation of alternators? Increase in reliability continuity supply is maintained All of these Increase efficiency under light load conditions Increase in reliability continuity supply is maintained All of these Increase efficiency under light load conditions ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. sf. sf / 2. f / s. s2. sf. sf / 2. f / s. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction effect is more in which of the following methods? None of these armature resistance control field weakening method same in both methods None of these armature resistance control field weakening method same in both methods ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If iron loss and full load copper loss of any transformer are denoted by Pi and Pc, then the load corresponding to maximum efficiency is given by (Pi / Pc)0.5 × Full Load. (Pi / Pc) × full Load. (Pi / Pc)1.6 × full Load. (Pi / Pc)2 × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc) × full Load. (Pi / Pc)1.6 × full Load. (Pi / Pc)2 × full Load. 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%. 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% 82.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The crawling in the induction motor is caused by high loads low voltage supply harmonics developed in the motor improper design of stator laminations high loads low voltage supply harmonics developed in the motor improper design of stator laminations ANSWER DOWNLOAD EXAMIANS APP
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