Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that both Eb and Td are unchanged Eb is zero, but Td is unchanged Eb is unchanged, but Td is zero both Eb and Td are zero both Eb and Td are unchanged Eb is zero, but Td is unchanged Eb is unchanged, but Td is zero both Eb and Td are zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole, 3-phase induction motor is running at 4% slip at full load. If the speed of the motor is 720 rpm, the supply frequency is 25 Hz 60 Hz 50 Hz 40 HZ 25 Hz 60 Hz 50 Hz 40 HZ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a polyphase induction motor helps to increase the starting torque. reduce the chance of crawling. reduce the magnetizing current. reduce the chance of cogging. increase the starting torque. reduce the chance of crawling. reduce the magnetizing current. reduce the chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series generators are used in which of the following applications? Arc welding. Used as boosters in dc distribution or transmission. All of these Air crafts. Arc welding. Used as boosters in dc distribution or transmission. All of these Air crafts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors. Calculate the back emf produced when it is running at a speed of 1500 rpm. 220 volt. 240 volt. 440 volt. 230 volt. 220 volt. 240 volt. 440 volt. 230 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has a rotor resistance of 0.002 Ω / phase. If the resistance is increased to 0.004 Ω / phase then the maximum torque will increase by 200% remain unaltered reduced to half increase by 100% increase by 200% remain unaltered reduced to half increase by 100% ANSWER DOWNLOAD EXAMIANS APP
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