Electrical Machines For a 3 - Φ, 4 pole, 50 Hz IM rotating at full load speed of 1440 rpm, calculate speed of rotor field with respect to rotor structure and stator structure respectively? 1440, 1500. 50, 1500. 60, 1440. 60, 1500. 1440, 1500. 50, 1500. 60, 1440. 60, 1500. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Semi closed slots or totally closed slots are used in induction motors, essentially to reduce magnetising current and improve power factor improve starting torque increase pull out torque decrease starting torque reduce magnetising current and improve power factor improve starting torque increase pull out torque decrease starting torque ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To increase starting torque of a 3-phase slip ring induction motor, preferred method is to increase supply frequency None of these rotor resistance supply voltage supply frequency None of these rotor resistance supply voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 50. 36. 80. 18. 50. 36. 80. 18. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Motor is driving a constant load torque having armature resistance of 0.25 Ω and armature current of 60 A having connected to a voltage of 230 V. Now a resistance of 1 ohm is added into the armature circuit. The ratio of their speed will be 0.72. 0.62. 0.25. 1.24. 0.72. 0.62. 0.25. 1.24. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω Xd = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω ANSWER DOWNLOAD EXAMIANS APP
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