What are the typical values of characteristic impedences of overhead line and underground cabel? Why there is so much variation?

1 Answers  

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what is power frequency withstand and impulse withstand of a circuit breaker?

2 Answers   Power Grid,

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different b/w counter poise and ground wire

1 Answers   L&T, TCS,

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Why is negative feedback invariably preferred in closed loop system?

0 Answers  

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how we can know which is Lv side and HV side of transformer by just seeing it?

7 Answers  

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How we can calculate the consumption in kwh of motor on basis of kw @100% load, @50% load & @ no load.

0 Answers   Grasim,

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What is servo motor and what are different types of servo motor

0 Answers   BARC, Vipul,

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what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the 94 lockout relay is activated when the distance realy is activated and 86 is activated when the 87T differential is activated. but why can't the same lockouts be used for both the protection schemes

10 Answers   ABB,

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Why CT secondary should not be kept open?

7 Answers   Anna University,

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what is the length of air terminal in lightening arrester system.

1 Answers  

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How to calculate amount of copper used in a motor (AC&DC), generator and transformer? Datasheet provides power rating and mass of the equipment....can we somehow use this available info.

1 Answers  

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How to calibrate or test an LT Air Circuit breaker 440 volts, 35 KA, 800 Amps ?

0 Answers   ABB,

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