Electrical Machines A three phase 400 V, 6 pole, 50 Hz, squirrel cage induction motor is running at a slip of 5%. The speed of stator magnetic field with respect to rotor magnetic field and speed of rotor w.r.t stator magnetic field are 1000 rpm, 950 rpm. zero, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. 1000 rpm, 950 rpm. zero, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines High inrush of current during a starting of DC motor can efficiently be restricted to a safer value by increasing the _________________ resistance. shunt field both A and B none of above armature circuit shunt field both A and B none of above armature circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC shunt motors are suitable for Lathes. All of this. Blowers and fans. Centrifugal pumps Lathes. All of this. Blowers and fans. Centrifugal pumps ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then I1 = I2 None of these I1 < I2 I1 > I2 I1 = I2 None of these I1 < I2 I1 > I2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 18.18% increase 36.36% increase 36.36% increase 36.36% decrease 18.18% increase 36.36% increase 36.36% increase 36.36% decrease 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%. 67.5% 78.5% 72.5% 82.5% 67.5% 78.5% 72.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
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