Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Swinburne test is conducted under which of the following condition? full load half load any of the above no load full load half load any of the above no 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%. 82.5% 72.5% 67.5% 78.5% 82.5% 72.5% 67.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting in a synchronous motor takes place when supply voltage fluctuates. when power factor is unity. motor is under loaded. when load varies. when supply voltage fluctuates. when power factor is unity. motor is under loaded. when load varies. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The short circuit test on a transformer is conducted to obtain hysteresis loss. eddy current loss. copper losses. core loses only. hysteresis loss. eddy current loss. copper losses. core loses only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A motor armature conductor of length 0.5 m is exposed to a flux density of 4 Wb / m2. Calculate the force experienced by the conductor, when the armature current is 5 Amp? Can't be determined. None of these. 15 N. 20 N. Can't be determined. None of these. 15 N. 20 N. ANSWER DOWNLOAD EXAMIANS APP
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