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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
What's the first test that should be carried out when working on a excisting electrical system?
1: Identify sources of supply
2: Isolate
3:Secure isolation
4:Test the voltage tester
5:Test the equipment is dead
6:Test the voltage tester
7:Begins work
How many amps does a 3 kva transformer draw?
The primary current of a transformer depends upon the secondary current which, in turn, depends upon the load supplied by the transformer. There is not enough information in the question to determine the rated primary and secondary currents of the transformer.
Ohm's Law: V = I*R, so Voltage and Current are directly proportional and a change in voltage will result in a proportional change in current. (The current reduces by the same factor)
The voltage at the service, such as a customer (your home, for example). This may be contrasted with the transmission, subtransmission, and distribution voltages used to get power from the generator to the customer.
Is transformer is essential for rectifier?
no transformer is not necessary for rectification today most of power supplies have been made without using transformer in order to reduce weight and size of power supply.for example SMPS(switch mode poqwer supply)
Power = Current * Voltage * Power Factor
Above expression can further be explore as :
1. For DC Circuits
Power = Current * Voltage
2. For Single Phase AC Circuit
Power = Current * Voltage * Power Factor
3. For Three Phase AC Circuit
Power = Line Current * Line Voltage * Power Factor
What is the form factor of sine wave?
Form factor is (RMS value)/(average absolute value)
For sine wave form factor = (1/sqrt(2))/(2/pi) = about 1.11
When using a swamp cooler can you use a rheostat to control the motor speed?
A: A swamp cooler uses water flow to control temperatures as the water flow increases the transfer function increases. So yes it will effect the temperature. but for humans at the same time more water in the air will effect our perspiration and cooling in effect basically it will reach an equilibrium whereby more water will not cool us any further. A 70 degrees and 100 % humidity is hotter then 85 degrees dry heat
What is a leakage current collector is?
I am in trade school becoming an electrician and i think what it is is simply a drain for a pool, whether it be a hydro-massage, portable, spa or hot tub and it allows extra water to drain properly. If there is any current leakage from a short circuit or anything in the water then it would be bonded because the leakage collector is bonded to the control panel. That's what i think it is .
Which term is defined as the value of a current sum of money at a specified date in the future?
It is called the 'future value' .
What are the disadvantages of bus duct?
Bus ducts no doubt compact, need routine checks for loose connections at joints. Any loose connections is not easily visible (to infrared scan) since they are enclosed. A poor quality out door bus bar, water can enter. These factors can make the busbar vulnerable. Where as cables, are more easily maintainable and are low on investment.
G.RAO
It works with two reactor coils for excitation of the field reactor coil , which in turn provides current to the field. The two reactor coils are connected in shunt and series with the output of the generator stator or armature ( from where load is connected).
Will a transformer Differential Relay act online to line to fault?
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The zone of protection for 2 , 3 or multi windings transformers differntial relay is decided by the location of CT.s at the respective sides i.e. HV. IV OR LV SIDES . Ideally on any fault within zones of these C.T.s the differential relay should act. However sometimes inadequecy of C.T. s ratings like low burden rating, less knee point voltage or improper biased settings may cause the differential relay to operate even on line faults.
Regards,
J.M.SHAH
What are the possible result of a tap changer malfunction?
Low voltage, high voltage, or a fault; the effects of these could be damage to equipment, including the transformer and tap cahnger.
What is the ampacity of an ACSR?
WIRE AMPACITY TABLE
ACSR DIA.(OUt) CCC
795MCM 1.093" 900 A
556.5MCM 0.927" 730 A
336.4MCM 0.721" 530 A
4/0 0.563" 340 A
3/0 0.502" 300 A
2/0 0.447" 270 A
1/0 0.398" 230 A
2 0.316" 180 A
4 0.250" 140 A
6 0.198" 100 A
What is working principle of generator and motor?
The principles of generators, motors and electromagnetism are the same.
They produce either Electricity, Magnetism or Spinning (Motor.)
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There are four parts of each equation, 1.) Magnetism, 2.) Conductors, 3.) Spinning or Windings and finally 4.) Electricity. Any combination of three of these components will produce the fourth, (with the exception being a conductor is not necessarily produced when the remaining three are combined.)
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Generators produce (E) Electricity through the use of (M) Magnetism, (S) Spinning or windings, and (C) Conductors or E = M + S + C.
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Motors produce (S) Spinning through the use of (E) Electricity, (M) Magnetism, and (C) Conductorsor S = E + M + C.
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Electromagnetism (M) is produced through the use of (E) Electricity, (S) Spinning or windings and (C) Conductors or M = E + S + C.
The capacitive reactance of a capacitor increase as?
The capacitive reactance of a capacitor increases as the frequency decreases.
The part of the armature that the brushes ride on is called the?
Motor brushes ride one the commutator.
What are the application of differential compound generator?
Differential compounded generators are used in Ward Lenard motor generator loops. The shunt fields on these generators are separately excited and when the shunt field polarity is reversed by the controller the series field helps drive the generator voltage to zero thus aiding in the reversal of current.
