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Induction Motor
Why transformer does not rotate like induction motor. Inspite both having same principle?
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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 -
Meaning of RJ11
Could you elaborate in detail about RJ11 and what does "RJ" and "11" stands for?
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Can we take Power supply for 1 phase fan from 3 Phase Compressor(Condensing Unit)
I have installed 3 Phase Compressor(Condensing Unit) and 1 Phase Evaporator(Fan).
In this 3 Phase Compressor requires Three Phase Supply and not Neutral (which is connected to DOL starter connected) and i want to take power supply for Fan which has phase and Neutral. Whether can i loop phase from the motor and Neutral from the Control Panel. Please tell me its correct or not. -
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Transformer Principle
Explain the transformer principle in terms of induced e.m.f. resulting from changing flux linkages?
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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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Transformer Humming
What causes transformer humming?
Krishna Kant Gupta
- Mar 13th, 2012
Humming sound in the transformer is due to the stray losses in the transformer due to the leakage flux.this flux produce eddy currents in the nearby conductive areas.The humming sound is the result of...
bittu123
- Nov 9th, 2011
Humming sound caused by magnetostriction phenomenon. Magnetostriction is change in physical dimension of material because of change in magnetic field.
Since, there is varying magnetic field in transformer causes vibration of core in gap available due to bad insulation. and starts soud hum -
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Power System
Why the transmitted voltage is multiple of 11 like 11, 22, 33, 132 etc? Is their any technical reason for that?
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Two phase motors
Why zero sequence component not found in two phase motors?
Harish P. Girhe
- Apr 3rd, 2012
In two phase induction motors one phase & neutral is applied. For successive working of motor one phase is spitted into two equal and opposite component. These two component are having an opposite action on each other.So two phase motor works successively.
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What is the use of a VCT
What is the use of a voltage capacitor transformer?
sjw06
- Apr 15th, 2012
VCT is used to step down really high voltage to a very low voltage that can be safely fed to a measuring device or protective devices.
Harish P. Girhe
- Apr 3rd, 2012
Generally all transformers works on inductive load hence operated at lagging power factor. It is necessary to use an capacitor bank for improvement an power factor. This capacitor bank called as VCT. Generally this VCT known as RVT (Residual Voltage transformer)
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Cable selection
Why Cable selection depends on Load current? (UG Cables & OH lines)
soumendasbiswas
- Apr 26th, 2012
Cable selection not only depends on the load current but also depends on Temperature, Length (Distance between LT Switchgear MCC/PMCC to Motor). If load is increase then current will also increase if ...
raju
- Apr 6th, 2012
Voltage is directly proportional length, current is proportional to area of cross section of the wire.
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Direction of current flow in three pole regulator
The circuit diagram is at http://avstop.com/AC/apgeneral/regulation.html
I cant completely figure out the way current is flowing through the three pole regulator that I have attached. I believe that current is coming up through the L1 coil into the positive terminal of the armature. and, I think current is flowing down through L2 coil and around back up to the positive terminal of the... -
Induction Motor Power Factor
A 3-phase induction motor running on 500v at full load draw 40A current at 0.85 pf Lagging if 85 micro Farad capacitor connected across its terminal than what would be a New Power Factor?
mahmoudp1
- May 1st, 2012
You didn't specify the capacitors connection is delta or star
assuming (delta)
Xc = 37.462 ;
reactive power drawn by capacitor = 6684.49 VAR
active power drawn by motor = 34641 watt
old power factor = .85 lag
new power factor = .91 lag
vishnu
- Feb 18th, 2012
--> Find the reactance offered by capacitor i.e 37.46 ohm. so leading current drawn by capacitor is 9.095A @90 deg lead. --> Current drawn by the motor is 40A @ 31.788 deg lag. --> Resultant current ...
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Circuit Breaker
Explain what are Single and 2 Pole circuit breaker?
mahmoudp1
- May 1st, 2012
Yes and single pole means that circuit switch two poles / two wires (eg; live and neutral)
3 poles used to switch 3 phase systems
4 poles used to switch 3 phase + neutral wire
5 poles used to switch 3 phase + neutral + ground wire
amolgaonkar
- Dec 9th, 2011
Circuit Breaker is a safety device used to safeguard electrical equipments from heavy current, it trips OFF when more than rated current passes through it.
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Making electricity
Can electricity be made by reversing. Other words can you make electricity by spinning magnets around copper wiring
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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.
Electrical Engineering Interview Questions
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