Answer / engr. kashif

All transformers are usually of smoke grey color
bcz this color is poor absorber of heat and a good radiator of heat.
so the transformer during its operation is able to radiate
its internal heat with the help of this color.

Answer / sarmadahmed

Their color is same because most of the transformers are made up of same material (soft iron core).

Answer / srikanta

This is a ISI standardise color for soft iron core

a starter used for squirrel cage induction motor?

0 Answers  

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v=I*R, i.e V is directly proportional to I. now P=V*I. so V=P/I. thus v is inversely proportional to I. so what is the correct one? If both are correct than for which kind of condition this 2 differ

3 Answers  

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any earth foult trip the relay but in welding time not trip by earth foult

0 Answers   Power Grid, Siemens,

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while conducting an experiment why we connect the armature rheostat in maximum position and field rheostat in minimum position

1 Answers  

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can v use earth as nutral. yes than y.if not y.

3 Answers  

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what is thermo stat, explain how its working?

1 Answers  

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what's producer of XLPE cable laying in undergroung

0 Answers  

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1. What is differential relay? How it operates? 2.How to calculate the Short Circuit Impedance in Transformer? 3.What is the alternate solution for testing of polarity by using polarity tester while its milli ammeter does not works? 4. While testing the 33KV Busbar by using Hipot kit, what should be the test voltage we have to apply? 5. What is the procedure/activities to be taken to inject the current more than 2000A by using 2000A Loading Transformer? 6. Explain how you can give the overload setting to any Motor Protection Relay for a HT motors with formula and example? 7. Why restricted earth fault protection is needed? Why can’t differential Protection is sufficient? 8. What should be the minimum and maximum ohmic value for earthing? 9. Why DC Currents are not used in transformer? 10. What is the Frequency while we step up the voltage from 220V to 11KV? Is it possible? Explain it?

0 Answers  

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in a delta-star with neutral grounding on star side what will happen if one star limb  got opened at star point

1 Answers   NTPC,

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What will happen if the rotor of an induction motor is fed from a 3 phase supply and the stator short circuited ?

4 Answers  

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directional over current relay when acted & how it works

3 Answers   NCC, ThyssenKrupp,

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How we can calculate the life of Lead acid battery

0 Answers   ABC,

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