Electrical Machines For higher values of armature, the speed of a DC series motor is Inversely proportional to armature current. Proportional to the square of armature current. Constant. Proportional to armature current. Inversely proportional to armature current. Proportional to the square of armature current. Constant. Proportional to armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA 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 speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 960 RPM 970 RPM 920 RPM 940 RPM 960 RPM 970 RPM 920 RPM 940 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the emf generated by the armature is maximum when rate of change of flux is minimum. rate of change of flux is maximum. shaft rotation is high. induced voltage is high. rate of change of flux is minimum. rate of change of flux is maximum. shaft rotation is high. induced voltage is high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 100 KVA transformer is operating at 60 Hz, 240 V supply. The same transformer is operating at 50 Hz, 200 V supply. The new rating is 100 KVA 50 KVA 123.3 KVA 83.33 KVA 100 KVA 50 KVA 123.3 KVA 83.33 KVA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When flux density is constant in a transformer, hysteresis loss varies as f² V V² f f² V V² f ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for voltage build up in self excited generator? Field winding should be properly connected to armature winding. Field winding resistance should be less than critical resistance. Poles should contain residual flux. All of these Field winding should be properly connected to armature winding. Field winding resistance should be less than critical resistance. Poles should contain residual flux. All of these ANSWER DOWNLOAD EXAMIANS APP
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