Explain What will happen when direction of field current is changed (i.e, field excitation is reversed) in the following machines? 1) Alternator 2) Synchronous Motor 3) D.C Generator ( Shunt or Seies ) 4) D.C Motor ( Shunt or Seies )

3 Answers   NTPC, Transco,

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When i went to a interview the interviewer ask me a question for that i cant able to answer him if anyone knows answer me How will you design a capacitor bank for a plant? if my p.f is 0.6 i have to improve it to 0.9 or 1 what kind of steps i have to do? and is there any formula for calculating this?

6 Answers   APNPDCL,

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we use 3 phase supply for induction motor why not use two phase supply .

4 Answers   TLC,

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how to calculate the cable size in sqmm if load (kw) is given?

5 Answers  

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critical losses of transformer

3 Answers   EEEC,

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I have a small system with two motors that are running on 380 vac, 60 hz. These motors are expensive and I usally get them from Brazil. I am adding another motor to the system, but I want to purchase a 480 vac, 60 hz motor to use. It will be on a VFD that is rated fro 380 thru 480. Is this posible and will I have to use a larger motor and derate it?

0 Answers   US Electrofused Minerals,

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If the rated speed of a d.c. Shunt motor is1440 r.p.m, which method of speed control would you suggested to obtain a speed of 1500 r.p.m?

0 Answers  

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the voltage per turn of a primary winding of a transformer is the same as the voltage per turn of the secondary winding of the transformer. why?

8 Answers  

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why supervision relay is used in incoming feeders?

1 Answers  

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Difference between ups and invertor

3 Answers  

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What happens when DC supply is given to transformer

4 Answers   CESC, IBM,

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plz tell me Motor IP formula

0 Answers  

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