Answer / saish n kharkar

In case of SF6 CB SF6gas is used as arc quenching medium in.
when CB trip the male-female contact (we can say fix and
moving contact otherwise) gets opened at the same time SF6 gas
at particular pressure enters between the contacts and quench
the arc, also act as a coolant and insulating medium.

what is the mechanism of operation of brushless dc motor why is it more wexpensive then ordinary permanent magnet motors

0 Answers   Lanco,

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what are the ''pitting rings''and how cn they be controlled in a series generator

0 Answers  

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Why in medium voltage system(3.3kv to 33kv, neutral is earthed with either resistance, reactance or neutral grounding resistance?

4 Answers   Essar,

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I have a CT meter with ratio 60/5. The meter reading of previous month was 3290.49 and that of current month was 3797.26. How many chargeable units as per normal meter should be my reading.

0 Answers  

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what is the difference between brush & brushless dc motor explain its operation ?

1 Answers  

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A 100 kVA , 400 v/250 kv testing transformer has 8% leakage reactance and resistance on 100 KVA base . A cable has to be tested at 500 kv using the above transformer as a resonant transformer at 50 hz . if the charging current of the cable at 500 kv is 0.4 A find the series inductance required . Assume 2% resistance for the inductor to be used and the connecting leads . Neglect dielectric loss of hte cable . what will be the input voltage to the transformer ?

0 Answers   L&T,

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How loading get increased in generator not the speed, while we increasing steam to turbine.

2 Answers  

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In a generator (Synchronous) does the rotor speed (frequency) corresponds to the speed of the water (in hydro). does the torque on the turbine relate to the flow of water?

2 Answers  

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why we use 50 hz frequency in india .. why not 60 hz 

3 Answers  

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Please explain, how to test vector group of tranformer(Delta y1) . Thank

0 Answers   PGCB,

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how voltage regulator works ?

1 Answers  

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Why annealing is done on transformer core manufacturing process?

1 Answers   ISRO,

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