Electrical Machines In a DC machine, the angle between the stator and rotor fields is 0o. 90o. dependent upon the load. 180o. 0o. 90o. dependent upon the load. 180o. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage to a dc machine is 230 V, then the back emf, for maximum power developed, is 200 V 460 V 115 V 230 V 200 V 460 V 115 V 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a motor falls from 1100 r.p.m at no-load to 1050 r.p.m at rated load. The speed regulation of motor is 3.76%. 2.57 %. 2.56 %. 4.76%. 3.76%. 2.57 %. 2.56 %. 4.76%. 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% 72.5% 82.5% 67.5% 78.5% 72.5% 82.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 5% 40% 10% 19% 5% 40% 10% 19% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 1 and 3 1 alone 1 and 2 2 and 3 1 and 3 1 alone 1 and 2 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
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