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.

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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

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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

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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.

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