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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Explain How pinch off occurs in MOSFET?

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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What is the difference between half controlled and full controlled rectifier? Why we go for full controlled while half controlled can control voltage?

k.r.kartheeswari

• Apr 10th, 2017

In Half controlled rectifiers, the controlled output will be in one half cycle, so the efficiency is less. But in full controlled rectifies, the controlled output will be in both the half cycle since both the sides having SCRs. So efficiency also doubled compared to half controlled.

pradeep1987

 Profile Answers by pradeep1987 Questions by pradeep1987

• Feb 4th, 2016

Diode is uncontrolled and SCR is fully controlled element. In SCRs we can turn ON and OFF by gate pulse or by the other means. Whenever the diode is used in rectifier, the rectification is done by the...

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How is UPF Wattmeter different from LPF Wattmeter?

Siva

• Apr 21st, 2017

LPF Watt meters are specially designed to measure the power at low power factor (inductive circuits).

UPF type Watt meters are not so accurate in measuring power at low factor (resistive circuits).

sharath

• Oct 28th, 2011

LPF watt meter is used for measuring power in highly inductive circuits & UPF watt meter is used for measure power in resistance circuit in which the power factor ranges from 0.5 to unity.

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What type of effects are produced in transmission lines due to mutual inductance and due to self inductance?

pradeep

• Apr 27th, 2017

Answer is both. The primary EMF in transformer is induced by the self induction, whereas the secondary EMF of the transformer EMF is induced by the mutual induction. Here is the main question what pri...

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If mutual flux is 1.2 Wb, power factor if 0.8 lag, then what is the useful flux of a Transformer?

Nitish saini

• May 9th, 2017

Mutual flux will remain constant 1.2 wb

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Why ceiling fan rotates in anticlockwise direction?

P.Raghavan

• Jun 13th, 2017

When fan stops suddenly and starts running in clockwise what is it due to?

amardeep singh

• Jul 30th, 2011

Flux is produce in clockwise direction and eddy currents makes fan to rotate in anticlockwise direction..........

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What happens if load increases when the generation is constant?

Mayilsamy Kasipandi

• Jul 11th, 2017

Load increases when power is constant - Result voltage drop depending upon the load

Ravi

• Mar 7th, 2017

The excess load draws more current from source. since the the power is constant in source side, voltage on load side drops and losses are more and power factor reduced.

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In a Manufacturing Factory, it is observed regularly the power cables are bursting resulting in fire even though branded cables are used. Identify the cause of bursting and guide to avert any future disaster of cable failure leading to mega fire accident.

Mayilsamy Kasipandi

• Jul 11th, 2017

Commonly two reasons.
1. Loose connection in the lug termination or connectors side
2. Cable rating is under capacity

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