Answer / rajeshsan

Brushes with metal will lead arc and more wear & tear, Hence for large rating we will use carbon brushes. And for toy motor and very small motor use metal brushes.

Answer / mohanavel.u ,marg ltd

The carbon brushes are having the self lubricating capacity
and if metal is used it will lead to more wear and tear
produces spark and damage the armature.

Answer / pavan msh

brushes used in dc machines are mostly made of carbon bcz carbon is of low cost and also a good conductor

how to decide the load on secondary of the tranformer

1 Answers   DLF,

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Explain the terms real power, apparent power and reactive power for ac circuits and also the units used.

0 Answers  

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why is only third harmonics is dangerous for electrical equipments?

3 Answers  

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how can we detect that which is receiving side and which is sendind end of a trnasmmison line by just seiing it?i.e its which end is coming from genertaing and distribution side?

5 Answers  

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Explain mechanical rotational system?

0 Answers  

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We have .ht motor which is 60Hz.we run on 50Hz.so that it's speed reduce but we had one prob.that motor winding temp increase up to 135 deg.we want reduce this temp.what to do?we arrange ext.cooling fan but not much effect.we want reduce this temp. Inhouse without affecting much.cost. also don't want reWINDING OF MOTOR?

3 Answers  

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how to calculate short circuit current for the busbar

0 Answers   HMK,

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Dear All, Can anybody please tell me which value(saturated or unsaturated) of sub-transient reactance(Xd") we take for the calculation of fault current of the system?

2 Answers  

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Why neutral is used in electrical system?

2 Answers  

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what is our body resistance value?

11 Answers   Bhel,

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what is meant by neutral Ct of a transformer and how it connected in transformer

4 Answers  

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Why alternators are rated in KVA?

12 Answers  

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