Electrical Machines High inrush of current during a starting of DC motor can efficiently be restricted to a safer value by increasing the _________________ resistance. both A and B armature circuit shunt field none of above both A and B armature circuit shunt field none of above ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Shunt Motor having shunt field resistance of 250 Ω and armature resistance of 0.5 Ω is connected to 250 V supply and load current of 21 A. What is the back emf generated ? 230 V. 240 V. 150 V. 210 V 230 V. 240 V. 150 V. 210 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM in order to eliminate cogging the number of stator slots must be equal to number of rotor slots. an integral multiple of number of rotor slots. either (B) or (C). unequal to number of rotor slots and skewed in shape. equal to number of rotor slots. an integral multiple of number of rotor slots. either (B) or (C). unequal to number of rotor slots and skewed in shape. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V dc machine has an armature resistance of 1Ω.If the full-load current is 20 A, the differenc in the induced voltages when the machine is running as a motor and as a generator is zero 40 V 50 V 20 V zero 40 V 50 V 20 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 1600 Volt. 1500 Volt. 0 Volt. 2000 Volt. 1600 Volt. 1500 Volt. 0 Volt. 2000 Volt. ANSWER DOWNLOAD EXAMIANS APP
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