I want to ask that is there any relation between current denesity of copper and material purity. also is ther any standard which defines the standard current denesity of material.

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why starting current is high and resistance is almost 0 during the starting of motor dc motor...?

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Why we use Electrical energy rather than any other type of energy, mostly? Explain behavior of open secondary CT and short circuited secondary PT in energized condition?

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how the 6.6KV motor can be used with 11KV?

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Why Lightning arrester used? Can we use piece of iron as a core material of transformer, if No, why? In CRGOSS material what is meaning of cold rolled grain oriented? Why Impegrenation of Transformer is done? Properties of Insulator? what is phase angle? Testing of transformers (Routine & Monthly)?

6 Answers   NTPC,

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is there any difference between protection C.T and measuring C.T?if yes then what is the difference?

4 Answers   BARC, Century Rayon,

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Transformer Parallel Operations

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What is the meaning of GRID?

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what are the different types of bus bar used at electrical work at shelter

3 Answers   Aster Teleservices, Costco,

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When we use air circuit breaker, it has O/L protection ,time delay SC protection, Instataneous SC protection & ground fault protection. They all have some setting range. But what is the suitable/allowable setting for the above protection which will be safe for the equipment? For example-O/L protection setting have a range of (0.4,0.45,0.5,0.55,0.6,0.65,0.7,0.8,0.9,1.0)xIn Time delay SC protection have a range of (1.25,1.5,2,3,4,6,8,10,12)xIn Time delay setting is 0.02,0.1,0.2,0.3,0.4 Instataneous setting is fixed to 20xIn Gound fault setting is given 100A,300A,600A,900A,1200A This setting are for 2500A ACB. So what will be the basic allowable setting for the above protection? is there any formulae to calculate this<

0 Answers   Lupin,

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What is the resistance of the field winding of a d.c. Shunt generator kept low?

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Explain thin film resistors and wire-wound resistors

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