Why dnt we generate 5-ph or 7-ph supply like as 3-ph supply

2 Answers  

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What is meant by rotor?

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what is power factor?

3 Answers  

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what kind of motors are used in the winders of coal field?and what are the various methods of it's speed control?

1 Answers   Monnet,

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i m in need of current rating chart of heavy duty pvc/xlpe, cu/al cables. can somebody provide me? if yes, plz send me at ashish_patel111@yahoo.com

0 Answers  

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formula for calculation of switchgears(i.e. contactor, fuse, cb, relay etc.), if load current is given?

0 Answers  

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What is the power factor,apparent power,reactive power and formula of power factor.

3 Answers   MNC,

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My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula. formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec. Sp = RT( I x I x t) / K Where Sp – is the cross sectional area of bus bar in millimeters. I -    is the value of AC fault current. t -    is the operating time of disconnecting device in seconds. K –  is the factor depending on the material of the conductor, insulation and initial and final temperature. Value of ‘k’ for copper is 143.

0 Answers   Premier,

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Can u tell me design of switch yard

0 Answers   NTPC,

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explain Density

0 Answers   TCS,

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When a square wave is applied to primary of a transformer then what will be output wave form of secondary ?

0 Answers  

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I have a transformer 3phase 11kv/410v and its name plate missing. now how can I judge its rated kva?

2 Answers   Coca Cola,

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