AC stands for alternating current, and means oscillating to positive and negative 50 or 60 times per sec.what?

Question

what is positive and what is negative?
whether positive carries positive current?,negative carries negative current.?
Then What is positive current what is negative current?
whether if we touch positive current what happen?
whether if we touch negative current what happen?

Answer 1

AC stand for alternating current. AC current can oscillate at whatever frequency (# times per second, usually expressed in Hertz, Hz) you want it to. However, the power that comes into your house oscillates at 60 in the US and 50 in Europe. This has to do with the development of electricity. They had to sync up the phases when they created it and they would do this by hooking up the two sources to lightbulbs that would flash at each peak. 50 or 60 times a second is about the maximum cycle rate visible by the human eye.

Positive and negative current denote which direction electrons are flowing.

Nothing will happen if you touch positive or negative current, just don't touch both at the same time.

Answer 2

In electricity some of the explanations given are just analogies to help your understanding. The same situation can be explained several different ways. You will see this if you go to a local library and read several different texts in parallel. Especially if you then slide over into electronics.
Unless you are at the connection point of the electrical service, and disconnect it; any wire might be deadly to you if it is the return side of a circuit and you provide a better ground.
Ground is the zero point and is literally ground; requiring a conductor driven into the earth deep enough to have good contact . Older homes were sometimes grounded by a clamp to the water service. This is no longer acceptable because pipes maybe replaced, in part, with nonconductive plastic (in this situation, the water it self may carry part of the load, and where ever the iron or copper pipe is wet, will begin electrolysis, an electriclly driven erosion). That is dangerous to plumbers.
If you use the graphic analogy for AC, there is a line for zero and a curve for electric potential, a sinus curve, or something close to a series of parabolas. From zero to a peak, back through zero to another peak and back to zero is one cycle. this amounts to one hz or hertz, if it takes one second of time. It can also be measured between peaks (two peaks on the same side), it is the same distance, or the same time.
While you are learning I recommend an analog meter with a reversing switch. Never touch a wire that you don't know whether it is disconnected; always find a good ground for your meter.

Answer 3

AC or Alternating Current, the type current found in homes and businesses around the world. AC current goes from zero to peak voltage positive, peak voltage to zero to peak negative, and back to zero. The number of times this happens in a second is its frequency. (Hertz) 60 Hz in North America, 50 Hz most elsewhere. In our normal lives it is found in 2 voltages, 110 VAC and 220 VAC. (volts alternating current) The actual range is 108 to 128 and about 208 to 229. In some cases you may have 440 VAC. This different voltage levels are reached by 2 110 volt lines and one neutral line coming into your building. The potential or difference between one of the hot lines and neautral is 110 volts. The difference between the OTHER 110 volts line and neautral is 110 volts in the other direction. So in effect you have 110 volts positive and 110 volts negative fiving a total of 220 volts difference between the 2 power lines. Notice I have not said anything of ground yet. These 2 lines come into your service panel and the neutral wire is connected to a ground, copper stake usually is used. this grounds the service. Look in a service panel and you will see your white wires (neutral) and your bare wires (ground) bussed to the same basic point.
While on color, it is standard code to have red as a 110 volt lead, black as a 110 volt lead, white is neutral, bare or green is ground. If you are grounded touching both red and black will send 220 volts through you. touching red and white or black and white or red and ground, or black and ground will give you 110 volts. Wall switches are always placed in the black/red wire, never the white or green or bare. Outlets are connected to black/red and white using the gold scews for black/red and the silver screws for the white.
In the making of certain electronic equipment, even though it is AC, there is a positive and negative. This is why one side of an outlet is longer than the other, and some power cords have a wide prong and a narrow one, or the funny looking round or square ends on the power cord.

And finally, none of this information was copied and pasted. It comes from working with electricity since 1970.

Answer 4

What is alternating is the voltage in a "hot" wire relative to a reference (constant) voltage called "ground" or neutral in the other wire. On the positive half of the cycle, current flows from the more positive voltage hot wire to ground and is able to do work (operate an electrical device). On the other half of the cycle, the negative half, the hot wire is at a lower voltage than the ground wire and current flows from ground to that wire, again able to do work.

So positive and negative current refer to the direction of the current. Both are equally dangerous.

Answer 5

AC current makes a sine wave. Positive current travels in one direction and the negative travels in the opposite direction. The effect of the current has when you touch has nothing to do with whether it is positive or negative. It has to do with the amount of current that the circuit has.

Answer 6

AC current is electrical current that builds up in one direction to a peak.. then decreases to zero and then flows backwards to a peak value.... then slows down again to zero.. and builds up forward again... over and over and over at some rate.

it can be created by many methods... alternators in cars are one example.. which produce AC voltage which is rectified to DC for use.

Standard home electricity in the USA is 60 cycles/second and in Europe it is 50 cycles/second (as mentioned earlier).

What direction electricity flows is a matter of contention between Physicists and Professional Electronics people... which flows where? do electrons move? or do protons? or both? As long as you stick to one method of calculation and keep it straight in your own mind.. your calculations will come out correct and you can do most normal electronics.... but standard electronic symbols may throw you.

Touching current? hmmm.. touching a terminal that has Voltage on it can do nothing to you.. or it may kill you.. depending upon how much voltage is present. I have worked on circuits that carried 900 Amps (900 coulombs of electrons per second) and I held both terminals in my hands without harm because there was a voltage potential of only 1/2 volt.. which was not enough voltage to create a dangerous current within my own body (50 milliamps in your body can kill you) because my body resistance was quite high (at least several thousand ohms).

Best bet.. get ahold of some basic electricity/electronics books and read up on it.. in this case.. ignorance CAN kill you!!

Answer 7

Little confused by your questions. Alternating current is current that is constantly changing in amplitude and that reverses direction at regular intervals. It can also be said that alternating current periodically reverses or alternates in polarity.
The number of complete cycles of voltage that occurs in one second is called the frequency of the voltage and is symbolized by the letter, f and is measured in Hertz. One Hertz is simply one cycle per second (cps).
Current always flows from positive to negative. Negative is also referred to as ground. I hope you are trying to measure with some type of meter and not trying to actually to touch anything.

Answer 8

i would like to agree with the person above me, negative is not ground. Please dont consider both of them the same. And the guy who said it teaches electronic theory.

Answer 9

bluesax2000 says "Negative is also referred to as ground."

Yes. But I would state it like this:

Negative is often incorrectly, confusingly and sometimes potentially lethally referred to as ground."

I would refer you to http://www.davidbridgen.com/earth.htm

Answer 10

complex factor. check out with bing and yahoo. this could help!