Electrical Machines In induction motors, there is large decrease in maximum power factor when the dispersion coefficient is ________________. increased. remains same. kept constant to certain value. decreased. increased. remains same. kept constant to certain value. decreased. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In Ward-Leonard method of speed control, the direction of rotation of motor is reversed usually reversing the connection of the generator field terminal. generator armature terminal. motor armature terminal. motor field terminal. generator field terminal. generator armature terminal. motor armature terminal. motor field terminal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 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 a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating winding are used to rectify the flux density waveform at interpole region. region under main pole. None of these throughout the air gap. interpole region. region under main pole. None of these throughout the air gap. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a DC Shunt motor if the load is decreased to some extent, what will happen to its speed? The speed will increase in proportion to reduction in load. The speed will increase abruptly. The speed will increase gradually. The speed will remains almost constant. The speed will increase in proportion to reduction in load. The speed will increase abruptly. The speed will increase gradually. The speed will remains almost constant. ANSWER DOWNLOAD EXAMIANS APP