how would u xplain the difference between AC & DC current, in layman terms?
374690
DC is Direct Current in which the electrons move in one direction through the wire all the time.\nAC is Alternating Current in which the electrons flow one way for a short time and then switch directions and flow the other way for a while.\nThe constant direction switching does not interfere with the work the electricity does if the devices using it are properly designed. Some devices, like incandescent light bulbs, work equally well with either type of current. Other types of devices, like transformers, depend on the constant switching to operate.
609875
first of all, 120/240 are standard voltages for AC power, not DC.  DC comes in all flavors.\n\nanyway: 2500 kilowatts DC?\n\nthat is 2.5 MEGAwatts.  \n\ni find this somehow hard to swallow.  when i worked at a particle accelerator there was ONE really big DC power supply that put out something like 1.5 megawatts.  it was the size of a small apartment, and required massive amounts of water cooling, was entirely custom built, and probably cost something on the order of a million dollars or more.\n\ni don't think there is any such thing as "usual" for a 2.5 megawatt power supply.  think about it - you're talking about nearly the power consumption of a small town.  anything liek that would have to be custom built.\n\n----\n\nok, having seen your additional details:\n\ni'm quite positive it's AC, not DC.  it also probably depends on what kind of generator it is.  to give you a rough estimate, here's an example of a 11.5MW turbodiesel generator on a cruise ship:\nhttp://www.ship-technology.com/projects/destiny/\nnote the output is at 6.6kV.  that would set the current at the output at around 1.8 amperes.  \n\nhere's some more information.  as you can see there is no real "usual".  \nhttp://www.ship-technology.com/contractors/electrical/abb2/\n\ncheers!
455913
DC (direct current) only flows in one direction.  AC (alternating current) is current which changes direction back and forth with a regular period.\n   The electrons really do flow.  If you look at the "drift", or physical motion of an individual electron, it is much slower than you might think.  In a 12-gauge copper wire carrying 20 Amps of current, the average speed of an electron is quite slow; about 1/250 of a mile per hour.  There's just so many electrons moving along so slowly that it adds up to a substantial current.\n   Why then, when you flip a switch, does the light turn on so quickly?  That's due to wave propagation, which is much faster.  Think of waves in the deep ocean; the waves can move quite quickly, but if you're swimming in it, you're not moving nearly so quickly.  You feel a slight up and down motion, but the wave may be propagating at 30 MPH.  The water itself is not flowing along across the surface at 30 MPH, but the wave is.\n    It is exactly the same with electrons.  While the wave is moving very quickly, the electrons themselves move very little.  In the wiring of your house carrying 20 Amps of AC current, the electrons are wiggling back and forth 60 times per second over a distance of about one thousandth of an inch.\n    However, the wave moves much much faster, when you flip the switch, the change in voltage travels along the wiring at very near the speed of light (it's slowed down about 30% below the speed of light by the plastic insulation on the wire).\n    With that prelude, to answer your questions:\n- the copper wire is not typically called an ion.  During current flow, an atom may hand its extra electron to the next copper atom, but it also gets an electron from the atom on the other side.  Thus, each atom always stays about neutral in charge.  This is described as the copper atoms forming a lattice through which the "sea" of electrons can freely flow.\n- a heater does not work by converting kinetic energy of electrons to heat quite the way you describe.  Instead, it uses the electrical energy available on the conductors of the power cord, which takes the form of electrostatic force of attraction which pushes electrons from the negative line to the positive line.  As an electron eneters the heating element from the negative line, it feels a strong force of attraction towards the other end of the heating element, which is connected to the positive line.  The electron accelerates due to this force, and speeds up somewhat, but it travels only a fraction of a millimeter before it collides with a microscopic defect in the lattice of the heating element, and decelerates and transfers its kinetic energy into vibration of the lattice of atoms of the heating element (i.e. into heat).  It then accelerates again, then hits another defect.\n   The main thing which distinguishes the metal of the heating element from the metal of the copper wires feeding them is that the heating element has a higher density of lattice defects (i.e. higher resistance).  An excellent analogy is American falls at Niagra, where the water approaches in a deep, broad stream moving relatively slowly at high potential (i.e. the negative copper wire), then tumbles down quickly under acceleration of gravity, losing potential, but hitting a bunch of rocks on the way down.  Hitting each rock slows the water down, and also transfers some heat to the rock, but after each impact the water accelerates again as it falls to the next rock.  Then, the water leaves at lower potential in another slow, deep stream (i.e. the positive copper wire).
372456
To measure ohms, DCV, ACV, Amps or what????
939377
UPS=uninterruptible power supply =battery backup\n\ninverter=what the other guy said = convert dc to ac = part of a UPS\n\nThe battery of a UPS is direct current (as are all batteries), and the inverter is used to convert that to alternating current for use of devices hooked into the UPS when regular power is lost.\n\nThe inverter also converts AC from the regular power source to dc to recharge the battery.
1088982
It's rather interesting actualy, alternating current is said to be four or five times as dangerous as direct current, because it induces more severe muscular contractions. But on the same token AC (alternating current) has a tendancy to throw you oh higher voltages, which means with AC you have a better chance of being killed by blunt trauma from being thrown against a wall.\n\nI hope this answers your question. :)
207943
I second that. If you look, one particular example is electron speed in a wire.  Do the calculation for 1amp of current flowing through a 10 cm radius copper wire and its speed is only on the order of a cm/sec.  Now you gotta ask how then do you communication so quickly over a wire if the electrons only travel at a snail's pace ;)
220789
Are you trying to convert AC to DC?  If it is, you want to use a rectifier.
591697
I don't know the exact definition, but they differ on the way they deliver energy.\nDC generators give electricity at a given steady voltage, but AC generators give electricity in an continuous alternating voltage.
1050520
Think about the simpliest capacitor. It is clear that two metal plates that don't touch won't let a DC current pass, right? But the spacing is very thin so that the plate's charges can effect one another. When you first put current (even DC) to a discharged capacitor, it charges up and for a brief time it does conduct current. How long? Well it will charge to 2/3 of the total voltage in RC seconds (where R is the resistance of the circuit). So when AC current is "fast" enough, the cap is constantly in a charge/discharge state and current flows. The effective resistance (reactance) of the cap is 1/(2*pi*F*C). So the resistance goes down as the capacitance and the frequency rises.\n\nThe inductor, on the other hand is just a coil of wire. Again, it is easy to imagine that it will conduct DC. But when you first apply current (even DC) to a coil, the magnetic field will interact with the coil and produce an opposing voltage. This only occurs when the magnetic field is forming or collapsing (remember, magnetic fields that do not move do not produce electricity). So right when you change the current, the inductor will "resist" the change, but if the current doesn't change, it is just a wire. The reactance of a coil is 2*pi*F*L, so the resistance increases with frequency and inductance.\n\nNow, combining inductors and capacitors is another interesting subject, but you didn't ask about that....
582168
who the hell knows. AC/DC is crap compared to alice cooper
989966
First, to the basics...\n\nAC is Alternating Current.  This means that the current moves in one direction and then the other, changing at a frequency of 60 time per second, its unit of measurement being Hertz (Hz).  The generator produces this current at very high voltages which are sent down the transmission wires to local substations, where the voltages are reduced to the familiar 110 volts which appears in your electrical panel.   At the transformer of the substation, the transmission lines to your house are isolated from the ground and "float".  This means that there is no path for the current to flow from either wire to the ground or to each other.  Now, in order to use the power (which is a product of the voltage times the current)  the current must flow through a load, which is any energy using device from a light-bulb to a toaster to the pump on you washing machine.  Since both sides of the wire (both the black (hot) wire and the white (neutral) wire) are isolated from ground to begin with, attaching the neutral to the ground does not provide a path for current flow.  Only if a path is made from the black to the white wire will there be current flow.   If we connect a lightbulb between the black and white wires, we will complete this circuit.  Remember that power (measured in Watts) is the product of Voltage (measured in Volts) and current (measured in Amps).  If we know the amount of Voltage (110V) and the power used (say 100W in a light bulb), we can figure that the amps used are 100W / 110V = ~.91 Amps.  If the circuit breaker is rated for 15 amps, it would require at least 17 of those bulbs to exceed the capacity of the breaker and cause it to trip.  I hope this clears things up for you...
1172658
Actually it's a question in physics. I will try to explain it anyway:\nassume we have two windings w1 and w2 with  n1 rounds and n2 rounds respectively. If an A.C. voltage of V1 is connected to w1 then a voltage V2 will be induced in w2, satisfying the following equation:\nV1/V2=n1/n2 and for currents we have: I1/I2=n2/n1\nand it doesnt convert ac to dc to do so we should use a rectifier such as bridge rectifier etc
516677
No.  The skin effect will cause the AC resistance to be higher than the DC resistance.  This difference is larger for higher frequencies and for larger wires.
31337
It is DC voltage.\n\nhttp://www.ecs.umass.edu/ece/allerton/papers1999/36/
892848
One of the most frequently used is E=IR    ;E =voltage    I=current   R= resistance. U can change this every way depending on the unknown.\n    Good luck
481957
Capacitors are built with a gap between the two conductors, or sides of the component.  So it is not completely accurate to say that they block direct current, because enough direct current applied to one side will jump the gap (think of a spark plug).\n\nHowever, applied in a circuit correctly, that is why it is said they block dc current.  Make sense?