What is the role of air gap in any electrical machine how does it affects induce emf??

A.Rajasekharreddy

• Sep 13th, 2016

Air gap is used to produce magnetic flux between stator and rotor. Air gap is more uniform for the production of sinusoidal EMF in alternators to eliminate the harmonics. Air gap is more in syn machin...

NITIN

• Aug 10th, 2016

Airgap is used to produce magnetic field between stator and rotor. Flux is produce in rotor winding, then torque develop and rotor is rotating, but if air gap is more between stator and rotor then more magnetizing current is required and also loss is more.

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adnan

• Sep 27th, 2016

The emf induced at power plants is sinusoidal AC, so it is not because of our choice. It is the natural simplest AC waveform that we obtain.

Neha bisen

• Sep 24th, 2016

Sine wave forms we can indicate the maximum and minimum amplitude and its variation with respect to time.

RMS value of sine wave is more than the other wave like square, triangular etc.

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What happens to extra power, if at an instant generated power is 10000 MW but demand is 8000 MW?

G. Gray

• Sep 28th, 2016

The so called "extra" power is dissipated throughout the systems often in loses such as heat etc.

prayag c nambiar

• Sep 26th, 2016

The extra power generated gets distributed through the grid it is connected.

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What is the physically meaning of form factor?

amit gupta

• Sep 29th, 2016

Form Factor = R.M.S. Value / Average Value = 1.11

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Srinath

• Oct 6th, 2016

Can you elaborate the reason why we have cos angle for active power and sine angle for reactive power?

ABC

• Sep 4th, 2011

Bcz in impedence triangle(cos=b/h) R(resistance) is in the base and imepedence is hypotaneous.
power factor(cos )=R/Z. THATS WY WE are using cos in the power factor notation.

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gagan.bhatia

 Profile Answers by gagan.bhatia Questions by gagan.bhatia

• Oct 25th, 2016

In electrical engineering, a synchronous condenser (sometimes called a synchronous capacitor or synchronous compensator) is a device identical to a synchronous motor, whose shaft is not connected to anything but spins freely.

romeo vincent

• Oct 18th, 2016

What is the advantage of capacitor used in ballast for discharge lamp?

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How much of power can I generate before connecting it to step up transformer presently?

Chand

• Nov 3rd, 2016

We can generate 11 kv

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Is a synchronous generator running a constant load has a longer lifetime than a generator running a variable load? If yes why?

Chandan dubey

• Nov 11th, 2016

It can be run but in practical there is necessary to change it. So if change in load in other gen. Will result change in current and load angle (angle between Sand v) and also change in active power, for which it will be need to arrange frequency regulating equipment, so overall cost will increase.

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What is the use of stator and choke in tubelight?

G.Harish

• Nov 19th, 2016

It gives initial current to bulb

rohansharma

 Profile Answers by rohansharma Questions by rohansharma

• Mar 26th, 2011

Choke Coil : for producing a very high voltage across the terminals of Tube Light.Starter : It applies that high voltage suddenly to the tube light filaments, which makes ionisation of the gases in the light.

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What should be earthing between Earth to Earth in industries ?
How we get no of earth pit in company.?

Devang

• Dec 8th, 2016

Earthing system depends upon the soil resistivity, to calculate the no. of earth pit. one should know the soil resistivity. only after that you may calculate no. of pits, treated or un treated earth p...

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deepak kapoor

• Dec 9th, 2016

True formula is Ns =120F/P

Sushil

• Oct 31st, 2016

Frequency is constant in a grid is because 1) All Equipment are designed for 50hz. Frequency 2) We genrate 50hz. 230 volts so in India all generation plant are 50hz. 3) All grid are inter-conected s...

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Is it a wise choice to use a brushless and commutor less dc generator as an alternate for inverter. Is it feasible to do so? From the knowledge I have when the rotor of DC GEN is rotated by external shaft, induced EMF is alternating current.?

Dhaval Parmar

• Dec 16th, 2016

Yes we can do it using controlling circuit it is called regeneration process first of all we create the rectifier circuit of o/p 48 volts 5 amp dc. this supply is given to the inverter bridge circuit ...

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Night time load on our system street lights, one DG battery charger-24v, 6 KVA UPS. On UPS only 12v solar fencing battery. You are suffering from leading pf. Can you say how to improve pf?

ashish dubey

• Dec 18th, 2016

We can improve the pf by reducing the harmonics.

vivek

• Sep 30th, 2016

By shutting down the capacitor bank.

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Gaurav

• Jan 13th, 2017

Capacitor causes a lag in the phase, resulting in a good starting torque.

manoj yadav

• Sep 1st, 2016

Capacitors provide phase difference between voltage and current and give starting torque

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Hashim

• Jan 19th, 2017

What happens on generator connected with grid if grid frequency increases or decreases

expertnayak

 Profile Answers by expertnayak Questions by expertnayak

• Jun 12th, 2009

Pole slipping typically occurs under severe fault conditions which cause a transient torque on the generator which exceeds the ability of the field to hold the generator rotor synchronised to the stat...

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How will you differentiate the transformer is LT or HT transformer whether belongs to Voltage range or MVA ratings. Explain?

B Vinod kumar

• Jan 21st, 2017

Depending upon the rating of transformer we can say, is that transformer belongs to LT or HT and we have to talk about transformer in VA only not in voltage of watts because, it is load less ie., There will be no power factor.

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1) What does active, reactive and apparent means practically?
2) What happens when variable frequency is passed through transformer?

tariq faridi

 Profile Answers by tariq faridi Questions by tariq faridi

• Jan 25th, 2017

If variable frequency is given to transformer then the EMF generated is variable due to which load varies a lot with change in voltage hence it will damage the windings of transformer...

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Why frequency should remain constant in Grid? If it varies then what will happen to other generators?

Ashu the Sharp

• Feb 2nd, 2017

Because Power will vary and rest of generators will loose sync

Jay-quellin

• Feb 8th, 2016

It synchronizes the generators, which would run out-of-phase if they dont all run at the same frequency. Power would not be constant. Imagine a digital and analog clock. The analog clock will keep tra...

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What is the flyback convertor?

Harita

• Feb 18th, 2017

Flyback converter is a buck boost converter used in the SMPS (Switch Mode Power Supply, small size and large frequency)

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When DC is applied, Transformer goes in to saturation, What happens if DC Pulses are applied, will this be safe? Will it act as transformer?

Pradeep Mewara

• Mar 29th, 2017

If we apply DC to the transformer, the nature of DC is constant magnitude so constant flux generate in primary winding there is no change in flux so EMF will not induce excepting when switch ON and switch OFF. If DC is continually supplied to the primary it will burn.

Ravi

• Mar 7th, 2017

When DC applied to Transformers the induced emf is zero in primary because of steady current, which leads to heavy current flow coz only coil resistance is connected directly to the source. Which dama...

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