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Phase Advancer
Why Phase Advancer is not used in below 200kva machine?
bittu123
- Nov 8th, 2011
During starting or low load condition IM works on very lagging current which results in taking high current. This sudden high current may creats transient in power system, which is undesirable. Phase ...
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AC Generator
To induce EMF, either field has to rotate or rotor has to rotate. In Alternator, AC supply is given to the armature to produce rotating magnetic field. The rotor is rotated by the prime mover. Then how will EMF be produced in an alternator. Explain the working principle of alternator in detail?
manilal.r
- Jan 2nd, 2011
Like a DC generator, an alternator also has an armature winding, but there is one importent difference between two, in a DC generator, the armature winding placed on rotor in order to convert AC? to ...
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Alternators
Which slots does a stotor of an alternator rarely uses?
veerateja
- Jan 22nd, 2011
Open type slots are used in synchronous motor or alternator because to reduce the leakage reactance and leakage flux,which increases if closed slots are used.
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Dielectric Strength
What is dielectric strength?
Harish P. Girhe
- Jan 4th, 2011
Material can be conductive or non-conductive. It depends on its di-electric property of that material. Di-electric means property of an material to oppose flow of electrical current. For better condu...
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Lightening Arrestor
Calculate the length and the distance coved by the lightening arrestor to be installed above 20 feet height industrial building.
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Power Measurement
Why current coil and pressure coil of wattmeter is connected in different phases for reactive power meaurement?
bittu123
- Nov 8th, 2011
You have to draw a phasor diagram. then U will get it easily. Draw Vr, Vy, Vb with 120 degree displacement. Now draw Ir leading(lagging) Vr by some angle, Say 0. and Iy displaced 120 degree to Ir, sa...
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Two Phase Induction Motor
What is a Two Phase Induction Motor?
sandeep.psg
- Mar 2nd, 2011
2 phase Induction motor(IM) has 2 sets(phase) of coil displaced electrically by 90degree. In practise we dont have dedicated 2 phase IM because of not supplying Constant Torque. But we do have so...
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Power Consumption
A heater of 1500w, bulb of 100w & 40w are connected respectively as sequence as stated above across supply. What effect will be observed on illumination/power consumtion of all of them?Now sequence is changed as bulb of 40w then heater & last bulb of 100w. What effect will be seen on illumination/power consumption of all of them?
Jai Pradeep
- Mar 13th, 2011
In the first method?the heater with 1500Watts connect, i.e large load is connected in first of a sequence so most power consumed by this. The 100 & 40 watts bulb will illuminated lighter.In the seco...
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Quiescent Point
What is a Quiescent Point (commonly called a Q-point)?
uttkarsh BIT
- Mar 26th, 2011
Quiescent or Q-point of any device is the intersection point of its characteristic curve and a given load line(or load curve). It actually is the most suitable point around which the device works under maximum efficiency.
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American Distribution System
What is the difference between American and Indian distribution system? Which one is better and why?
bittu123
- Nov 8th, 2011
AMERICAN : frequency 60Hz House hold voltage: 120v and 240v Split phase 3 wire service INDIA: frequency 50 Hz House hold voltage : 230v and 4...
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Induction Motor selection
Could you explain that how to select an induction motor for a specific mechanical load(inertia). is there any formula or calculation then please give me. i shell be very thankful to all of you.
mahmoudp1
- May 3rd, 2012
First know the load specifications like power needed or torque and from the catalogues choose the correct motor without any calculations.
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Software testing and Embedded testing
Briefly explain the difference between the software testing and embedded testing?
I need the brief explanation please provide the details as early as possible -
Contactors in circuits
Why we use contactors in ckts....how many types of contactors are there.. how we select the contactor for in ckt for its operation
bittu123
- Nov 8th, 2011
Contactor is basically a large relay kind of thing which is used to switch large amount of power. It has multiple contacts and all contacts can be switched together. all multiple contacts are controll...
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Earth Fault
What is the technical difference between earth fault and earth lekage relays ?
bittu123
- Nov 8th, 2011
Earth fault : If live wire gets touched to the earth, heavy current start flowing through this wrong path, causing short circuit and considered to be a kind of fault. Earth leakage relay: Instrument ...
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How to run three phase induction motor as a generator
Abushama
- May 29th, 2011
Since the induction motor and Generator have the same constructor then running a motor as a generator is possible . if we want to run ?induction motor as a generator two things should be done , First...
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CT Earthing
Why ct earthing should be connected at one end only? if ,we connect more than one end means what will happen?
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Why ct earthing should be connected at one end only?
If we connect more than one end what will happen?
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Harmonics
What is the necessity of harmonics in electrical field?
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Why 3 colors Red, Yellow and Blue ?
Normally we represent the three phases, RED, YELLOW, BLUE for identify the phase shift of the phases.
Why not other colors, any reason for that? Or “R Y B” colors are the basic colors.
Electrical Engineering Interview Questions
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