What are the applications of potential transformers other than metering and under voltage protection?

Raman Jain

 Profile Answers by Raman Jain Questions by Raman Jain

• Dec 29th, 2010

There are numerous applications of Potential Transformers .1. For Metering Purpose.2. Required for Synchronisation of Feeders / Generator with Grid.3. For Feed back of AVR.4. Distance Protection of fe...

ripago

 Profile Answers by ripago Questions by ripago

• Nov 28th, 2010

1. Over/Under Freq. Protection2. Syncrhonizing Generator to Grid.3. If you don't have spare of PMG then you can use this PT for AC Power supply to the excitation Unit of your own Genarator.

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Why is it that the secondary voltage of a step-up transformer is lesser than the primary voltage of a distribution transformer?

Jai Pradeep

 Profile Answers by Jai Pradeep Questions by Jai Pradeep

• Mar 13th, 2011

The primary voltage of a distribution transformer decreases due to increase in length of the conductor between step-up and distribution transformer.

Nico Dishanth

 Profile Answers by Nico Dishanth Questions by Nico Dishanth

• Dec 26th, 2010

It is due to ferranti effect.

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what is capacitor bank. Where it is used & why it is used

mrtelco1948

• Jan 6th, 2013

It is a proven fact that Capacitor banks cause an a.c. humm on copper telephone lines. In some cases, power companies have agreed to remove the capacitor banks when they caused this problem in entire neighborhoods. This was discovered by Bell Labs Noise mitigation experts many years ago.

gaurav vinayak

• Aug 23rd, 2011

capacitor banks are basically used for power factor improvement. they are used by companies distributing power, due to induction load at homes and industries, power factor lags and to correct it and b...

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vipul prajapati

• Sep 12th, 2011

It is the machine for the purpose of lapping.Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.

sujay chavan

• Sep 9th, 2011

Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.

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Moruttak

• Dec 12th, 2011

Power(active power)=voltage* component of current in the direction of voltage.
Thus if power factor angle is theta, current component in the direction of voltage is =magnitude of current * cos (theta) .

harish kumar

• Sep 21st, 2011

As you know cos theta is what its the angle between the voltage and current. so at one time voltage lead the current and at other intent current leads the voltage. these are called the leading and...

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Why there is a fivefold increase in a current at electric motor start-up?

eng: ahmed gharieb

• Dec 5th, 2011

Every thing in the first being hard but with time it get better. The IM is one of this thing, as in the start n=0 so that the equivalent cct of IM
exactly as before

Thanks

bittu123

 Profile Answers by bittu123 Questions by bittu123

• Nov 8th, 2011

If You may be talking about DC motor, here is the explanation........ current through rotor is given by i=(V-E)/R. But during starting no emf is induced, E=0, So, i= (V-0)/R must be greater than if ...

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soomnath paul

• Feb 2nd, 2013

High resistance is connected in order to make the voltage appeared across the pressure coil in phase with the applied one.

mahmoudp1

 Profile Answers by mahmoudp1 Questions by mahmoudp1

• May 1st, 2012

We connect more resistance in series to make the total resistance is high so that it wont absorb any power (amperes) for the circuit so i wont affect on the true reading and also the series coil to me...

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In the car alternator is a 3 phase generator and rectified instead of using dc generator.

Why ac alternator is better than dc generator in any car?

ripplenwinder

 Profile Answers by ripplenwinder Questions by ripplenwinder

• Dec 11th, 2013

No! 3 phase has no rectifier or voltage regulator a car alternator does. DC the voltage and current are suppose to be 180 degrees out of phase from one another or so most people think. Current can go ...

suryatejreddy

 Profile Answers by suryatejreddy Questions by suryatejreddy

• Apr 12th, 2013

DC generator although produces a.c,it must be converted to d.c by rectifiers in order to store in the batteries and to it supply must be dc,so in cars instead dc generators alternators are used.

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Can the transformer be operated on current source instead of voltage source ??if ,, what will happen ?

somnath paul

• Feb 2nd, 2013

In case of an ideal current source , it will deliver same current irrespective of the load connected to the secondary terminals thus proper transformation will not take place in order to maintain constant flux.

S.Ghosh

• May 23rd, 2012

I assume that by current source you mean constant current source. In such case the primary and secondary voltage of the transformer will depend on the impedance of the transformer and the load. The lo...

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If I got a 380v 3-phase supply and I want to rectify it with thyristors to single phase how much voltage will I get ?What is the relationship?thanks

SGhosh

• May 15th, 2012

The dc output of the full wave rectifier is average value the amplitude of the sine wave. In short multiply the r.m.s value of the ac input voltage by its form factor (1.11 in case of pure sine wave) ...

mahmoudp1

 Profile Answers by mahmoudp1 Questions by mahmoudp1

• May 15th, 2012

I know the output will be dc my question is how much dc voltage will be the output

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What is the relation between kva &kw

rajender

• Nov 5th, 2012

Apparent power(KVA) is the total power from the supply, active power(KW) is the usefull power at load.

reena upadhyay

 Profile Answers by reena upadhyay Questions by reena upadhyay

• Nov 4th, 2012

Apparent p(S)=active p(P)+reactive p(Q)
s=kva=i*v
p=i*vcos@=i*V power factor=s*power factor

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Why do not we use salient pole alternators in thermal power stations?

umeshprabhu

• Mar 11th, 2013

The Salient pole alternator because of its large diameter and short axial length takes more time to complete one revolution for a pair of poles under a coil, so the frequency of induced emf which is p...

cmallick1201

 Profile Answers by cmallick1201 Questions by cmallick1201

• Jan 8th, 2013

Salient pole rotor has larger diameter than cylindrical rotor. In thermal power plant rotor should rotate in high speed so that salient pole will unstable due to larger diameter so that we cant use salient pole in thermal power plant.

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ULAGANATHAN

• Oct 3rd, 2013

Voltage exist only for a closed circuit whereas emf exist for a open circuit.

vehvariya

• Sep 23rd, 2013

Voltage is the potential difference applied between the two terminals, where as EMF is the electromotive force induced in the conductor due to the voltage because of the floe of the current.

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Why we are preferring 4 pole alternator in the production of electric power instead of 2 pole alternator ?

vijay kumar

• Oct 19th, 2015

Number of poles are chosen to get 50Hz frequency for a given speed. n=(120*f)/p

s.asokan

• Jul 28th, 2014

Speed is depend on number of poles and frequency. Commomnly all motors are used 1500 RPM and Indian standrad frequency 50hz also motor used 4 pole. In rare case nearly 3000 RPM (high speed motors, ht alternators) machines are used 2 poles.

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in ac circuit what is return neutral , When its happenng & why ......

PRADEEP VERMA

• Dec 12th, 2014

Neutral link make a return path and make close path because current is flow in close path

anand bhavsar

• Nov 27th, 2014

I think its when neutral wire has got since your device is not getting neutral it will show voltage on its neutral terminal as well as circuit is incomplete.

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What is the operating range of voltage and current in grid supply in india?

priyank333

 Profile Answers by priyank333 Questions by priyank333

• May 10th, 2015

It depends of which ever load would applied & based on that it could supplied through source with that voltage & current with regulation.

TAPAS MOHANTY

• May 5th, 2015

The voltage can deviate in between +6 to -6 from its rated value.

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Which of the following options relate to a Multi User OS?
UNIX
Windows
Mac
All of the mentioned options

Turbo

• Jul 23rd, 2016

UNIX

srilaya

• Apr 9th, 2016

UNIX

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What percentage of system overhead will not result in poor performance for user programs?

>10%

>20%

GANESAMOORTHY

• Mar 28th, 2016

>20%

Avinash

• Mar 1st, 2016

>20%

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Co-operative switching means that a task that is currently running will voluntarily give up the processor at some time allowing other processes to run. State True or False.

TRUE

FALSE

sountharyaraja

• Jun 9th, 2015

True

narsimha Vuggepalli

• May 29th, 2015

True

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What are the roles, responsibilities and work of an electrical engineer in a cement plant?

Asfandyar Ali

• Aug 10th, 2016

Troubleshooting of Electrical Fault, Maintenance of electrical Equipments, Inspection of Electric Motors.

gokul pawar

• Jan 19th, 2016

Role is in the same inspector for the finding out the more consumption area and improve it because in cement industry there is max. use of electricity

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