A capacitor, resistor and inductor are connected in series as well as in parallel also. Is energy storing in those three elements are same? Explain

What is the main difference between Transformer based UPS and Transformer less UPS and its operation?

Dheeraj Rai

• May 22nd, 2016

Transformer Based UPS Transformers in general are used for number application, the most obvious one is to stepping up or down the voltage. In UPS application they are also used: To create galvan...

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What are the advantages & dis-advantages of Harmonics in Power System?

Qaphelani Sgcino

• Apr 2nd, 2016

Disturbances in the communication networks and telephone lines.

Kevin

• Mar 27th, 2016

Disadvantages of Harmonics: Harmonics degrades the performance of power system. Some of the disadvantages of harmonics in the power distributed network are listed below: The harmonics flowing in the...

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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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When alternator is over exited, the power factor will be
a. Lagging
b. Leading
c. Zero

Dipti Ranjan

• Mar 7th, 2016

Pf is lagging because A.R is demagnetizing.

pradeep1987

 Profile Answers by pradeep1987 Questions by 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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mani babu amballa

• Mar 5th, 2016

When the charging coil is disturbed suddenly, it will produce large amount of voltage

shubham

• Aug 31st, 2015

Choke work like transformer and its major components which is connected Across its inductor Stores current like caps

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How can we make wattmeter to measure reactive power?

Amol takate

• Jan 27th, 2016

For calculation of the reactive power in 3 phase connected load procedure is to connect the current coil of single phase wattmeter in any phase series with the load and connect the pressure coil acros...

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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?

mohammed

• Jan 18th, 2016

If we want to distribute to customers we use star connection but if we want to trasmit power we use delta connection

pdp

• Jan 13th, 2016

Delta star connection generates 73.2% more than dd and yy connection because star side requires less insulation than delta side in normal condition..we can put extra insuation to generate high voltage...

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What is meant by distributed winding and concentrated winding?

karthik

• Jan 20th, 2016

Concentrated and Distributed wiring definitions

Ravikumar Eta

• Jan 10th, 2016

In concentrated type winding, all the winding turns are wound together in series to form one multi coil.

In distributed type winding, all the winding turns are arranged in several full pitch or fractional pitch.

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How does Slip Power Recovery System work? How to capture supply for recovery? Is it any possibility to design model of slip power recovery system drive?

Santosh

• Jan 10th, 2016

Of course, there are different methods to recover the power wasted in rotor and that is done by using Scherbius Drive or Kramers Drive where the rotor terminals are connected to a rectifier and again...

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you have three boxes, one has a resistor, second has a capacitor, and the third has an inductor. Find what is in each box, using a battery, a switch and a lamp. You can build any circuit you want, to figure out which box have a resistor, and which one has the inductor, etc. How can you solve that?

chandramvs

 Profile Answers by chandramvs Questions by chandramvs

• Jan 3rd, 2016

Connect the battery, switch, lamp and the box in series and observe what happens, 1) If the lamp glows with constant brightness then the box has resistor. 2) If the lamp initially is dark and finall...

abdelmonsef

• Jan 2nd, 2016

A battery is DC, so when connecting the battery and the capacitor and the lamp in series, the lamp will not be on (as the capacitor is open circuit in DC system) and when connecting the battery and th...

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What is the difference between Earthing & grounding?

chandramvs

 Profile Answers by chandramvs Questions by chandramvs

• Jan 3rd, 2016

Earthing and Grounding are nearly same where we connect the live parts of the machine to the zero potential(generally taken as ground or earth) in order to provide a bypass or excess or stray currents...

Rahul Patil

• Dec 24th, 2015

What is value of current flowing through earthing or grounding?

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I have acquired numerous individual speakers two sound bars and two sub-woofers and I am looking to make a surround sound for my home theater but not sure how to connect them all together.

What is the purpose of Q-point in transistor?

MADHUSHREE SINHA

• Nov 9th, 2015

It is a DC operating point between saturation and cutoff. It must be selected in a way that it does not go into saturation or cutoff.

bala

• Oct 24th, 2015

It is more important for a transistor because according to this value, it may operate as an amplifier or a switch and most importantly the point should not vary with temperature hence we normally prefer voltage divider bias.

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We are using neutral in Star Circuit and same in Delta Circuit is not used. What is the reason? Explain in brief.

Maheshkanna

• Nov 9th, 2015

Neutral is used to close a circuit but delta circuit is already closed so the neutral connection not used in delta circuit.

bala

• Oct 23rd, 2015

Normally delta connection is arrived by connecting two terminals of successive phase in a closed path and there is no common point of reference. But in case of star network one terminal is common to all phase thus creating a neutral.

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Why does Table Fan rotates Clockwise while Ceiling Fan rotates anti-clockwise? Any technical reason?

Nitin Banegaon

• Oct 29th, 2015

Normally, any motors rotates in anticlockwise direction as seen from non driving end. So in ceiling fan blades are attached to non driving end. So it seems to rotate in anticlockwise. While in table f...

shaik abrar

 Profile Answers by shaik abrar Questions by shaik abrar

• Jan 17th, 2010

When we provide supply to the stator of ceiling fan emf is generated. The set up of rotor and stator in ceiling fan is such that due to flux emf generated is in clockwise direction. As ...

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A) IDMT relay are mostly used for protection against?
1) Earth Fault 2) Inter turn fault 3) Overloading 4) None of the above

B) Which device is provided as backup of buchholz relay?

C) Name any two devices used for protection of power transformer against internal faults?

Manojkumar1990

• Oct 25th, 2015

A) IDMT relay is mostly used for the protection against overloading
B & C) REF & differential protections are used to protect the power transformer from internal faults and one of this both protections may used for backup of Buchholz relay.

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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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What is Phase Swinging or Hunting in Induction Motor?

Sushma vasudev ningappanavar

• Oct 14th, 2015

Swinging

Hari

• Oct 12th, 2015

When a synchronous motor is used for driving a varying load, then a condition known as hunting may occur. Hunting may also be caused if supply frequency is pulsating (as in the case of generators driv...

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Why 2-phase induction motors are NOT used in industries even though they have rotating magnetic field.

abhinav Kumar

• Sep 6th, 2015

Two phase motor essentially use in domestic use like water pump set ... It gives high torque and low efficiency. The phase diff 180 or 90 make the two phases with the help of capacitor.

anilsabaji

• Mar 11th, 2012

2 Phase motors have low efficiency and low power factor. There are higher chances of stalling.

MOST IMPORTANT: 2 phase load will create imbalance in the power system and high current and bulky too. Why should we use it when we have more efficient 3 phase induction motors

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