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Roles and Responsibilites of Electrical Engineer in Cement Plant
What are the roles, responsibilities and work of an electrical engineer in a cement plant?
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Star or Delta Transformer Selection
How can we chose transformer star to delta or delta to star connection? What condition is suitable for star connection? What condition is suitable for delta transformer?
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Electrical Power Factor 0.4
If you are an electrical engineer in a factory what will you do if you found power factor 0.4?
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Over Exited Alternator
When alternator is over exited, the power factor will be
a. Lagging
b. Leading
c. ZeroDipti Ranjan
- Mar 7th, 2016
Pf is lagging because A.R is demagnetizing.
pradeep1987
- Jan 31st, 2016
It is lagging. When the alternator runs at lagging power factor, the armature reaction demagnetize the main field flux. To compensate the extra magnetic field required so that the alternator is Overexcited
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Can Neutral be Earthed at Load Side?
Neutral is connected to Earth at the source to ground, the unbalanced current in the electrical network mainly in distribution system, What happens if we connect neutral to earth at load side DB?
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Convertion of Energy
Can mechanical energy be directly converted into electrical energy? Explain
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Is it possible for a feedback surge to travel over a wireless connection? Would the answer be different in a vacuum?
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Earth has the constant potential so we take it as reference.but in steo & touch voltage we use to calculate voltage of ground in 30 inch. How it is possible if no current can flow through ground?
Rahulshelke
- Jul 12th, 2010
During fault to have shortest resistance path is ground. Hence current flows through ground. hence we take 30inch during calculation.Voltage difference is created and current flows.
zakeer
- Aug 30th, 2007
We are taking earth as reference it means it's?potential is not absolutely "ZERO" but approximatelly it is zero .and the potential is not equal allover the earth it varies from place to place so we measure at 30 m in to earth
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Why we are using Sinusidol wave in all electrical systems?
SURAJTHEGREAT
- Apr 19th, 2011
We know flux(phi)=NBA cos(teta)e=-d(phi)/dttherefore on differentiating we gete=NBAw sinwt.ie.sinusoidal wave.Moreover when 3 phase are displaced by angle 120 with respect to each other,rotating magnetic field is produced.
cvk
- Oct 6th, 2007
Reson 1 is the way power is generated. Due to the construction of generators, the default wave form is sinusoidal. Secondly, the frequency of sine wave is a single definite value while other wave form...
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Why the generators are made such that they generate only sinusoidal wave?
rahulr30
- Jun 8th, 2008
Sine wave is best suited for commercial generation purposes because it will have a single unique frequency. I f we genrate a square wave ( by using concentrated windin in alternator) the problem of harmonics would arise.
cvk
- Oct 5th, 2007
It is by the natural construction that a sine wave form is generated.
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Syncronous Machines Slip
In syncronous machines, less slip is useful or more slip is useful? Why?
venky_sastra
- Dec 28th, 2008
A synchronous machine is defined as a machine which rotates with the constant speedslip= Ns-Nr/Nssince in syn m/c Ns=NrS=0The significance of slip comes only in induction machines where the slip exists.
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Reactive Power
What is mean by reactive power? How it is generated?
Sreebai
- Sep 21st, 2010
Reactive power is the power required to transmit the active power. The reactive power is like an envelop,that is used to send a letter. Without this we cant send the active power and it cant be too hi...
SURAJTHEGREAT
- Mar 3rd, 2009
We know reactance (hypothetical resistance) which reduce the supply voltage by opposite flowing induced emf. This power loss due to reactance is known as reactive power. This power is not useful power. It is a waste. However it is useful in determining the phase angle.
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Form factor
What is mean by form factor of the AC current?
Mohammad Ibrahim
- Jul 21st, 2011
2) In electric motor terminology, a form factor is the amount of rectified current emitted from a direct current (DC) power source and is expressed as a ratio of the root-mean square (rms) value of th...
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Power Supply Phase
Why do we use a single phase and a three phase power? Why dont we use two phase or four phase upward?
bittu123
- Nov 10th, 2011
Continuing my answer............... I wrote above "Differentiating single and double phase is really a big task. As single phase stand alone don't work, it always need neutral(returning path), U may ...
bittu123
- Nov 9th, 2011
As we increase the phase, output rating of machine also increases(like output rating of 3ph is 1.5 times more than 1 ph),pulsation in output decreases, this really encourage to have greater phase BU...
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Line Wire
When we touch the line wire or supply wire we get shock. What is that? Is it voltage or current or something else?
Harish P. Girhe
- Jan 14th, 2011
Voltage is responsible for electric shock. In house wiring only 5 or at least 10A current flows but potential diff. of 230V get disturb our nervus system. Human body(dry) can sences above 80volt without any danger.(Not every time)
_punjabi_
- Aug 29th, 2010
When you happen to touch the live part of the supply, then your body acts as a part of the circuit and of the Supply system is not grounded and if equivalent resistance of your body is less than that ...
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Electrical Machine Operation
In a 50hz electrical machine what happens when we use more than or less than 50hz?
mahmoudp1
- May 14th, 2012
Frequency affects on the speed and torque of the machine and thats is the principle of the drives
_punjabi_
- Aug 29th, 2010
Speed and torque of the Electrical machines can be regulated by chanigng the supply frequency. Also harmonics produced are different than normal operation
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Distribution Tower
What types of tower & pole is used in power system distribution?
mahmoudp1
- May 14th, 2012
For lattice metal structure (High Voltage )
they can divided into (specifying the job)
suspension , angle , end , cross towersraviiisc
- Sep 8th, 2010
I think "_punjabi_" forgot about the concrete poles or towers.These towers are more practical in now a days in Power distribution sector.
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Describe How energy is stored in a inductor on electronic level
George
- May 14th, 2007
Energy is stored in an inductor in the form of a magnetic field.
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How do we select a cable for a machine as per standards. Is there is any standard to select a cable as per voltage, or as per KVA and as per amps ratings?
prafulla patil
- Nov 15th, 2010
Cable size depends upon current carrying capacity and operating Voltage of Machine to select cable size also the Distance from the Supply Panel to Machine and way of laying cable under ground or on ca...
jatin patel
- Oct 16th, 2007
Cable size depends upon current carriying capacity and voltage to withstand,to select cable size we must have knowledge of load of machine and operating voltage
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