Answer / nilkanth tailor

In old technology UPS, thier is transformer used to step
down the voltage and givet to that circuit..coz at that
time we have no power equipment like ( IGBT, MOSFET,
BJT)..But now by using IGBT or MOSFET, we can make ups
without any transformer..in modern UPS thier is no need for
any transformer..so we can reduce the size of UPS by using
this power device./..

Answer / aravind

use toroid transformer or pin type transformer it consume
low space compared to normal transformer..

what is disadvantages of high power factor

4 Answers  

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why the voltage transmission is always in a multiple of 11? e.g. 110 V, 220 V, 33 kVA, 11 kVA

16 Answers   IAF, MahaGenco,

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I If i have 2kv ups in which 38Amp *8battries hou many hour's back up i get from 600Watts

2 Answers  

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which connection is safer series or parallel?usually which connection we prefer at home?

5 Answers  

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Why we are designed only 11Kv and 6.6Kv Alternators, not 33Kv Alternators and Power Transmission side we are designed only 220kv, 120kv, 66kv, 33kv, 11kv, and 440volts, not 20kv, 50kv, 100kv.

2 Answers  

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when the motor was star position that is running ok but when the motor was delta it was tripped? why?

5 Answers   Nimbus, SEL Manufacturing,

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1- XC and the RC time constant are both measures of the reaction of C to a change in ____? 2-The power factor is a numerical ratio with a value between 0 and 1 equal to the ______________ of the phase angle. 3-When V and I are out of phase because of reactance, the product of V times I is called ______________ power 4-For _____________ inductors, the branch currents can be added algebraically. 5- The ______________ power in watts can be calculated as I^2R 6-Calculate XL with L = 30mH and f = 1kHz ( I have Xl=2piFL 2*3.141592653*1kHz*30mH =188 ohms Please check) 7-A parallel RL circuit has the values, R = 5kohms, XL = 5kohms. A voltage source of Vt = 10Vrms is connected in parallel to R and L. Determine the total current, It delivered by the voltage source Vt. 8-A series RC circuit has R = 1Mohm and C = 1microF. How long would it take for the capacitor to fully discharge if it is initially fully charged? 9-A circuit has real power = 300W and an apparent power of 500VA. Determine the power factor and phase angle. 10-The time constant for an LR series circuit is T = 0.1s and R = 10ohms. Calculate the inductance L.

0 Answers  

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oltc of a transformer, how it works? and what are the equipment consist of describe briefly?

0 Answers  

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Explain using drawings what is reverse PID action w.r.t PID controllers.

0 Answers   L&T,

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what perpose of use CT ratio in gt,st,uat

1 Answers  

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how many maximum nos of add on contact we shd provide on 4 no contactor

1 Answers   Accenture,

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IN MCCB AND MCB TERMINATIONS ARE IN-COMING ON TOP AND OUT GOING ON BOTTOM,IF WE TERMINATED INTERCHANGED TOP AND BOTTOM ITS WORKS?

2 Answers  

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