Electrical Machines What is the emf generated by a 4 pole Lap connected DC Motor rotating at 1500 rpm having 1000 conductors and useful flux per pole is 0.4 mWb. 10 volts. 20 volts. 40 volts. 30 volts. 10 volts. 20 volts. 40 volts. 30 volts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In V/f speed control of 3-phase induction motor, with increase in frequency, the slip at which maximum torque occurs either of these. None of these decrease. increase. either of these. None of these decrease. increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An IM cannot run at synchronous speed because rotor torque will not be produced. air friction will prevent it. induction motor will become synchronous motor. none of above. rotor torque will not be produced. air friction will prevent it. induction motor will become synchronous motor. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following DC generators has rising V-I characteristics? Compound. Shunt. Series. None of them. Compound. Shunt. Series. None of them. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a 3 - Φ induction motor is clockwise when it is supplied with 3 - Φ sinusoidal voltage having phase sequence A - B - C. For counterclockwise rotation of motor, the phase sequence of the supply should be A - C - B. C - A - B. B - C - A or C - A - B. B - C - A. A - C - B. C - A - B. B - C - A or C - A - B. B - C - A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque the inequality of air-gap flux on the top and bottom halves of the armature is removed the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the interpoles produce additional flux to augment the developed torque the inequality of air-gap flux on the top and bottom halves of the armature is removed the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation ANSWER DOWNLOAD EXAMIANS APP