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How to Simulate an Induction motor?
jatin patel
- Oct 16th, 2007
Transformer with secondary shorted is simulation of sq. cage induction motor
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Induction Generator
Is it possible to run the induction generator only with the inductive load (without the use of capacitors for supplying the reactive power)? Explain
bittu123
- Nov 9th, 2011
I believe, You must be trying to ask "Will induction generator generate power with only inductive load??"... No, never....... Proper working of IG(Induction Generator) must need two thing 1. speed h...
anupam_srivastav
- Oct 2nd, 2009
We use capacitor in single phase induction motor to produce displacement in two winding which consequently produce rotating feild, now we can have a similar effect by using shaded pole method, but used only in small sized motor (40w
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Floting Earth
What is meant by Floting Earth? What will happen if we use regular earthing instead of floting earth and Where do we have to use only floting earth.
sn_rangari23
- Sep 28th, 2009
Floating Earth used in High Voltage equipment for high voltage Pit-Earth Test carried out for Transformer, Generator, Compressor, cables etc. for checking the condition?of moister & dryness of the cable.?
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Wattage related to Frequency
A motor rated 230V, 50HZ taking 100KW no load amps, what happen if just frequency goes to 60Hz?
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Transformer Sound
Why do you get a typical sound when the transformer is put into operation?
nikhilsharma2009
- Sep 15th, 2009
Transformer noise is caused by the phenomenon magnetostriction. When a piece of any magnetic sheet is placed in the magnetic field it gets magnetised and elongate. But when the magnetic field is remov...
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Alternator Operation
If we put field winding on stator and armature winding on rotor then how will it operate? Will it rotate at synchronous speed or not? (Assuming that the alternator is feasible)
nikhilsharma2009
- Sep 15th, 2009
Yes, It would surely operate and run at synchronous speed. But it would be uneconomical because we should have 3 slip rings of very high current handling capacity and because of this efficiency will decrease and we will require to have high level of insulation and cooling also.
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Induction Motor
Why star point of star connected motor is not grounded?
rajakumar1985
- Sep 10th, 2009
Normally the 3 phase induction motors are not star connected. In the star connected machine, the phase voltage will be 1/ 3 times. So that the torque of the machine will be reduced. Because of this reason normally all the induction motors are having delta connected field windings.
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Circuit Breaker
Which Circuit Breaker is better either Air CB or Vacuum CB? Why?
rajakumar1985
- Sep 7th, 2009
The vacuum C.B is better than A.B C.B for medium voltage because of its better operation and longer life. But in high voltages we cant use the vacuum C.B.
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Use of DC machine
We have enough category of AC machines more relliable than DC machine then why we are using DC machines in some application yet?
rajakumar1985
- Sep 7th, 2009
Each AC and DC machine having its own characteristics.According to the reguirement, the motors will be selected. Also the availability of supply is taken into consideration. But normally AC is preffered than DC due to its low maintenance and relaiability.
shravan.rawal
- Sep 4th, 2009
Take an eg. of DC series motor, it's properties are suitable for Railway engine, at the start it has high torque and low speed and once the core gets saturated it's torque is low but the speed is higher, so for this kind of special requirement we require DC M/C
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Rated Voltage and Frequencey
Why OC test is carried out at rated voltage and frequency?
rajakumar1985
- Aug 10th, 2009
Normally the OC test is done to find out the losses. The losses depends on the voltage and frequency applied to the machine. So that while testing, the rated voltage and frequency are applied to the machine.
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When there is a sudden loss in the demand what happens to the transformer and generation?
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csbalu- Member Since Aug-2009 | Aug 29th, 2009
When there is a sudden loss of load, The Generator terminal voltage increases due to the fact that the IX drop in the generator winding decreases. The EMF generated being the same the reduced reactance loss leads to a sudden rise in generator voltage..but the AVR (Automatic Voltage Regulator) will act instantly to bring this voltage to the set value by reducing the excitation.
There is practically no effect of this on the transformer barring the reduction in I2R (copper Losses) and reduced IX drop.csbalu
- Aug 29th, 2009
When there is a sudden loss of load, The Generator terminal voltage increases due to the fact that the IX drop in the generator winding decreases. The EMF generated being the same the reduced reactanc...
spcspc1654
- Jul 19th, 2009
When there is a sudden loss in the demand then there is over-excitation of the generation and the power factor is increased. Also the rotor angle of generator is changed (unstable) for a while.
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Insulation resistance for of generator
What is the value of insulation resistance between Neutral and earth of a 65 KVA Generator?
csbalu
- Aug 29th, 2009
First of all let me clarify this,Insulation value does not depend on KVA rating of the Generator.It depends only on the rated voltage of the Generator.The insulation resistance is measured between the...
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Circuit Breaker
What is single and 2 pole circuit breaker?
OLIELCTRICAL
- Aug 18th, 2009
Single pole only connect in phase incoming and out going line the load. Single pole holes top one & bottom one. max rating - 25 amps. Two pole?connect in phase & neutral. 2 holes top two & bottom two. max rating - 32. example mcb.
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Does HVDC mode of transmission has an economic advantage over EHV-AC transmission. Justify
sainathdi
- Aug 16th, 2009
HVDC- High Voltage DC Transmission system ,from the name itself we can say that its a dc transmission system and a dc transmission has two conductors one phase and other neutral. phase conductor is us...
venky_sastra
- Dec 28th, 2008
HVDC means high voltage DC transmission. Usually when we speak in common terms power p=I*I*R therefore p is propotional to I*I, A high voltage will generally involve low current so as a result the power losses are less. So it has an economic advantage over EHV-AC transmission.
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Measure DC Current
How can we measure the DC current directly?
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Voltage Standing Wave Ratio
List the basic ways of determining the voltage standing wave ratio in a transmission line.
naveed_ahmed
- Jul 13th, 2009
VSWR is a ratio of? Vmax to Vmin or Imax by?Imin?which can be theoretically?determined by using smith chart or practically determined by using vswr meter.
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Power Factor
What is the power factor?
bashir varsi
- Jun 14th, 2009
Power factor is the ratio of active power to apperant power. for better energy efficiency it should be unity.
jeet29
- Jun 8th, 2009
Power Factor means that what amount of the power the circuit is using. If the power factor is .807 that means circuit is using 80.7% of power and the remaining 19.3% is returning back to supplying source.
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60Hz Transformer
What would happen if a transformer is made to operate at 60Hz instead of 50Hz ?
expertnayak
- Jun 8th, 2009
In transformer eddy current lossesPe=Kv^2 it is not dependent on frequency so only hyteresis losses will get affectedPh=KfB^x
jeet29
- Jun 8th, 2009
If we are connecting a 50 hz transformer to a 60 hz transformer then there?hystersis and eddy current both losses increases considerably (for detail check effect of frequency on transformer losses).
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Motor Starting
The single phase induction motor starts with two phases(Using capacitor). Why can't the three phase induction motor starts with two phase?
jeet29
- Jun 8th, 2009
For the starting of a single phase motor we need two different fields and the resultant of both the fields works as the operating field revolving the motor in the direction of strong field (for more...
Electrical Engineering Interview Questions
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