Whats meant by trivector meter where it is connected at the
substation?
Answer Posted / nirupa chaturvedi
A Kelvin bridge (also called a Kelvin double bridge and in
some countries a Thomson bridge) is a measuring instrument
invented by William Thomson, 1st Baron Kelvin. It is used to
measure an unknown electrical resistance below 1 Ω. Its
operation is similar to the Wheatstone bridge except for the
presence of additional resistors. These additional low value
resistors and the internal configuration of the bridge are
arranged to substantially reduce measurement errors
introduced by voltage drops in the high current (low
resistance) arm of the bridge [1].It consist of two ratio
arms. The outer ratio arm contains the known resistors and
the inner ratio arm helps to connect the one terminal of the
galvanometer at the appropriate point (which was the
disadvantage of the Kelvin first bridge).
Principle of operation
The measurement is made by adjusting some resistors in the
bridge, and the balance is achieved when:
Resistance R should be as low as possible (much lower than
the measured value) and for that reason is usually made as a
short thick rod of solid copper. If the condition R3·R`4 =
R`3·R4 is met (and value of R is low), then the last
component in the equation can be neglected and it can be
assumed that:
Which is equivalent to the WheatstoN
| Is This Answer Correct ? | 0 Yes | 2 No |
Post New Answer View All Answers
What conditions are required for transformer to operate at low frequencies ?
1. Why is the speed of shunt motor practically constant? 2. Why dc series motor use to start with heavy loads? 3. advantages & disadvantages of separately excited generator over self excited generator?
Why human body feel electric shock?
Give some differences between open loop and closed loop?
how to remover corona effect and hysteresis losses from contactor
How to calculate the Harmonics losses in terms of cost/unit.
Work done in a free expansion process is
what is mean by restructuring power system?
Can anybody please refer the best and simple book for about Protection relays and in detail of all its protection ?
What is Meter MF if External CT Ratio is 150/1 , PT Ratio is 132/110 Meter CT Ratio is 200/1 & Meter PT Ratio is 110/1
In parallel operation time both NGR’s close or not close if both close what will happen
Hi I'm doing my MBA(3rd semester).I applied for the post of ET conducted by BHEL the last year.I cleared the written and lost in personal interview.Again I wrote the exam this time and cleared the written n yet to take the personal interview.Shall I disclose in the interview about my studies.What shall i say if they ask about my change from studies to job
what is difference between line differential and transformer differential?
Why the efficiency of generator is more than motor in swinburne's test
at work we have a 3 phase motor but on testing one phase isnt getting a reading. it runs 24 hours a day all week. stops and starts well no noise or heating. the phase isnt down to earth.is it just a bad meter reading or not? phases one and three came up with a resistance reading of 0.4 but phase 2 couldnt get anything shows up as open circuit.