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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 is the best power transformer brand?
Emerson brand, is the best power transformer (one person's opinion).
..What do you mean by "Best"? "Best" can be defined as:
1. Cheapest
2. Smallest
3. Most efficient
4. Quietest
5. Most resistant to through fault current, overheating, over voltages, etc.
or a mixture of the above (and other reasons that I haven't mentioned).
Capacitors are said to be connected together "in parallel" when both of their terminals are respectively connected to each terminal of the other capacitor or capacitors. The voltage (
Vc ) connected across all the capacitors that are connected in parallel is THE SAME. Then,Capacitors in Parallel have a "common voltage" supply across them giving:VC1 = VC2 = VC3 = VAB = 12V
Which material follow ohm's law?
All materials do, with the possible exception of semiconductors
and junctions between them under certain circumstances.
What is discrimination factor of electrical circuit protection?
Electrical discrimination is to do with selecting the correct protection in the fault path of an electrical circuit.
To illustrate, if you have a machine at the end of an electircal circuit and that is protected by a 13A fuse lets say, and then you have a 20A circuit breaker protecting that at the consumer unit (fuse board), and then the main switch on the consumer unit is a 10A circuit breaker, then every time the machine uses more than 10A of power the main switch will trip and disconnect everything connected to it, that is where discrimination is not achieved.
Basically it is where the circuit protection closest to the macine is smaller and it gets bigger as it goes boack to the source, then discimination is achieved.
I hope that helps. If not then it probably need a drawing to help answer.
Exactly...you answered your own question.
Each DC bulb will drop voltage according to its resistance and the amount of current it draws.
What generational group witnessed the switchover from analog to digital and hard wired to wireless?
The baby boomer generation witnessed the switchover from analog to digital and hard wired to wireless.
Whether you use 50 Hz and 60 Hz in the place where you live or work happens to be for historical reasons.
If you want to see more detailed information please see the Related Questions shown below.
Is silver tarnishing a physical or chemical change?
Silver tarnishing is a chemical change. It occurs when silver reacts with sulfur compounds in the air to form a layer of silver sulfide on the surface. This chemical reaction changes the composition of the silver, resulting in the tarnished appearance.
because Ford needed to have some competition! :)
Durant needed a holding company for the stock trading he did as his Buick Motors were being sold to McLaughlin Car Company in Canada for 15 years and McLaughlin traded 500,000 shares of his Company for 500,000 shares of Buick, The shares McLaughlin held in Buick stock were traded for General Motors Holding Company stock. R S McLaughlin was Director of the Company when Durant made a bid to buy Ford for 8,000,000 and the Bankers gave Durant 5 years away from his title in the Company allowing him to start Chevrolet in 1911.
What are the RMS voltages of X-ray machines?
If by RMS voltages you mean what is the RMS voltage of the power source voltage to the device proper it might be 120 volts AC like right out of the wall where you plug it in. That 120 VAC is an RMS voltage. That's the way we measure AC voltages like those wired into residential and commercial settings. Picture an AC sine wave. For a sine wave that is 120 volts RMS, its peak voltage will be right at about 170 volts. Volts RMS is the so-called DC equivalent voltage. The RMS voltage for a larger X-ray machine could be 220 VAC or 440 VAC, too, as higher power units are available. These units can be fixed or "permanent" in a medical setting or in an industrial plant, and can take advantage of higher electrical bus voltages. The X-ray tube itself runs on a DC voltage. A DC voltage doesn't usually have the idea of RMS associated with it. The voltage is "fixed" and not changing over time like it does in an AC source. Modern X-ray tubes can have operating voltages that range from 10 kV to 300 kV applied to accelerate the electrons before slamming them into an anode target.
How many amps are in a 12 volt battery?
Read the label to find out how many ampere-hours worth of charge the battery can store.
If it says "60 ampere-hours" then, if it is in good condition, it should be able to deliver a current of near to 60 amps for 1 hour or 30 amps for 2 hours or 1 amp for 60 hours, etc.
The condition of any battery will deteriorate over time: depending on its original quality and the kind of use it has been subjected-to. Like most things in life, the more you pay for something, the better quality you will get, you only get what you pay for! If it is subjected to very heavy discharges, such as often having to crank a very cold car engine for several minutes - which could take 600 amps on a big engine - then its normal life span could be severely reduced.
So, depending on its original quality, after an initial period of from 3 to 5 years, you must expect a battery's ampere-hour capacity to reduce more and more until eventually the battery will not hold any useful charge any more and it will have to be replaced.
If the voltage has a peak value of 100v what is the rms value of the voltage?
Peak values times 0.707 gives the RMS value.
This question cannot be answered without knowing the waveform of the voltage.
If it is continuous direct current rms value is 100V.
If it is a sine wave (like house current), the rms value is 100/ (sq. root(2)) or 70.7V approx.
For a regular series of square pulses, it is 100V times the mark/(mark+space) ratio.
Any other waveform, you need to calculate the root mean square value of the function. ( Square, integrate and take square root over one complete period.)
If all the above fail, measure the heating effect in a 40K resistor. It will be 0.25 Watt or less - calculate from the result.
What is a measure of force with which negative charges flow called?
The force that causes negative charges to flow is the electromagnetic force. And we often apply the term voltageto the force that causes electron current to flow in what we normally think of as electricity.
How is a Residual Current Device or RCD different to a Ground Fault Circuit Interrupter or GFCI?
Nowadays terms Residual Current Device or RCD and Ground Fault Circuit Interrupter or GFCI refer to the same type of electrical safety device.
If there is no fault anywhere in a circuit supplying single-phase alternating power to a unit such as an electrical appliance, machine or other equipment, the current flowing to the unit at any instant in the "hot" or "live" wire should exactly match the current flowing away from the unit in the neutral wire. Similarly, there should be no current flowing in the unit's safety "ground" or "earth" wire.
It is a basic fact of electrical engineering design that all current flowing to an electrical appliance, machine or other equipment from the power generation station via its supply circuit's "hot" or "live" wire should only return to the power station via that same circuit's "neutral" wire.
So, as a result of that basic fact, if any current isflowing in the ground wire, it must be caused by a fault condition and the supply of current to the circuit needs to be stopped urgently. Many years before today's electronic RCDs or GFCIs were designed, much simpler electro-mechanical relays called Earth Leakage Circuit Breakers (ELCBs) were invented so that, if any such ground current exceeding just a few milliamps was detected, they would "trip" - meaning "operate" - to break the current supply to the circuits for which they were installed to protect.
An Earth Leakage Circuit Breaker was the first name given to what is now called a Ground Fault Circuit Interrupter (GFCI) . The original type of ELCB or GFCI was designed only to detect a current flowing in the safety "ground" or "earth" wire.
So the original type of ELCB or GFCI did not check for any difference in current flowing in the live and neutral wires, a difference that would be an indication of another type of serious fault condition. Such a fault can be serious because, even if no current can be detected flowing in the ground wire, the "missing current" may actually be flowing to ground via someone's body!
After miniature electronic circuits were invented the invention of RCDs became possible: an RCD constantly checks for small differences in the currents flowing in the live compared to the neutral wire and for any current flowing in the earth wire. If any such "fault current" is detected, the device is designed to act very fast to shut off the supply of power to the circuit and the unit(s) it is protecting, because the "missing current" may actually be flowing to ground via someone's body!
That is the reason why, when RCDs were invented, most manufacturers of GFCIs adopted the same technology because it offers so much more protection to users than the original GFCI could ever give.
In the US and Canada such devices are still commonly known as "GFCIs" or "GFIs" even though they have the additional "residual current detector" functionality, whilst in Europe and elsewhere the more accurate name of "Residual Current Detector" or RCD has been widely adopted for general use instead of using the name of the originally much simpler GFCI device.
For more information on all these topics see the answers to the Related Questions and the Related Link shown below.
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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
What is effect on amplifier output if you increase input impedence?
Impedence is synonymous with resistense. Greater the I, lesser the output
No.
First, it's *resistance* and *impedance*.
Now, if the amplifier is a current amplifier, the above makes sense. (higher Zin, less Iin for a constant Vin).
But if it's a purely voltage amplifier, it only responds to the input voltage, so the impedance (so long as it's not affecting the source/driving device) will have no effect on a purely voltage-amplifying amplifier.
An instrument to be able to really tell the value is mandatory that the instrument does not load the circuit making it a false reading or inaccurate
loading effect which means when we give high load that may be cause to some fake or inaccurate of output, this may be known as loading effect....
The answer to the first part of your question is yes but the wire size has to be of a size specified in the electrical code for wires connected in parallel. As for the second part of the question the total current output is governed by the current draw of the load. It is the load current that governs the parallel wire size and the trip capacity of the breaker.
What type of transformer has only a single winding?
the auto transformer is the one winding transformer. it ismaily used in practical purpose.
First we need to know the total resistance which means all series resistors add up and all parallel resistors equal the reciprocal of the reciprocal of the resistances added together.
R1 = 10ohm
R2 = 12ohm
R3 = 4ohm
( 1 / ( (1/R1) + (1/R2) ) ) = 5.4545ohm *approx
R = 5.4545 + R3 = 9.4545ohm *approx
Now that we know the total resistance we can use Ohm's Law to find current.
I = E / R (I = Current, E=Voltage, R=Resistance)
E = 20v
R = 9.4545ohm
I = 20 / 9.4545
So our Current is approximately 2.1153948
Using a scientific calculator will yield a more precise approximation
What is the reason for a negative ground system?
Modern vehicle ignition systems use a negative ground system.
The reason some older vehicles used a positive ground system was because their manufacturers did not realize that metal erosion caused by sparking causes the center electrodes of the engine's spark plugs to be eaten away by the sparks if that electrode is connected to the negative side of the ignition coil's high tension output.
Such erosion can quickly make the spark-gap too large, causing late (aka "retarded") ignition problems which can seriously reduce the power output of the engine.
So, when using a positive ground system: a) the spark plugs had to have their spark-gaps adjusted every one or two thousand miles and b) the lifetime of the plugs was only around 5,000 miles or less.
Explanation
It is a fact of physics that, after millions of sparks, due to metal erosion there will be less metal on the electrode that is connected to the negative side of a dc (direct current) ignition coil.
So the center electrode of a spark plug will not erode away due to sparking if it is connected to the positive side of the ignition coil's high tension circuit and will erode away if is connected to the negative side.
As the spark plug's outer casing is much larger in area than its center electrode, if it is connected to the negative side of the ignition coil's high tension output, the erosion of the outer casing caused by sparking is hardly noticeable and this fact has the additional benefit that the spark-gaps of the plugs hardly ever need to be adjusted during their lifetime which, nowadays, can be well over 20,000 miles.
How do you convert a DC generator to ac alternator?
Turn the DC generator inside out and you have an alternator .
What is the venin and norton equivalent circuit comment?
I think you mean 'Thevenin'! You need to check out an electrical textbook, as this is too complicated to explain without illustrations.
