NounWikipedia has an article on: Alternating currentSingular alternating current Plural alternating currents alternating current (plural alternating currents) (abbreviated as AC)
From Wiktionary under the GNU Free Documentation License. In alternating current (AC, also ac) the movement (or flow) of electric charge periodically reverses direction. An electric charge would for instance move forward, then backward, then forward, then backward, over and over again. In direct current (DC), the movement (or flow) of electric charge is only in one direction. Used generically, AC refers to the form in which electricity is delivered to businesses and residences. The usual waveform of an AC power circuit is a sine wave, however in certain applications, different waveforms are used, such as triangular or square waves. Audio and radio signals carried on electrical wires are also examples of alternating current. In these applications, an important goal is often the recovery of information encoded (or modulated) onto the AC signal. From Wikipedia under the
GNU Free Documentation License By stepping up the voltage of an alternating current source using a transformer? Q. By stepping up the voltage of an alternating current source using a transformer, can we increase the amount of electrical energy drawn from the source? Asked by Margo Lamont - Sat Aug 15 16:36:22 2009 - - 4 Answers - 0 Comments A. no, because a transformer stpes - up or steps-down the AC voltage at the cost of decreasing or increasing the current. the values of AC power, in otherwords the energy of AC will remain constant. Answered by knr - Sat Aug 15 16:44:15 2009 True/False questions about alternating and direct current? Q. Alternating current (AC), rather than direct current (DC), is used for the distribution of electric power. Answer true or false. DC transformers are useful for transmission of electric power. AC transformers are necessary to produce low voltage for consumers. Very high voltage has greatest efficiency for distribution of electric power. Transformers can change the voltage for AC. Edison promoted the use of AC. All electric generators produce AC. Asked by kcguy13@prodigy.net - Tue Oct 28 15:38:18 2008 - - 1 Answers - 0 Comments A. 1, True, AC is used for power distribution. 2. False. A transformer is an AC device. 3. True. 4. True. The higher the voltage, the lower the current. Losses in the wire depend on the current flow, not the voltage. This is why transmission lines run at very high voltages (200-700KV) and distribution lines (the wires at the top of the telephone poles) run at 13 KV or so. 5. True (Transformers can change AC voltages). 6. False. Edison liked DC, Tesla liked AC. AC won out, because of the transformer issue. Particularly at that time there was no practical way to step-up or step down DC voltages. 7. For commercial electric power, this is true. However, there are generators which can produce DC, so in a general sense, this is false.… [cont.] Answered by mark p - Tue Oct 28 15:55:08 2008 How does the frequency of alternating current affect wire resistance?
Q. If power output remains the same, and frequency doubles, wouldn't the amplitude, or the current, be cut in half, thus reducing wire resistance? Asked by Al Bundy - Fri Aug 8 01:08:14 2008 - - 2 Answers - 0 Comments A. in the wire table we have dc resistance and ac resistance, dc resistance will not be affected by frequency. for 3/0 single conductor 60 hz due to ac resistance. the actual resistance value is roughly 1.004 times the dc resistance. thats why transmission lines has to watch out for the separation distance between conductors. for higher frequency the resistance increases heavily due to skin effect (eddy current), the current does not travel through the solid copper area anymore but through the outer surface of copper conductor, the relationship between frequency and wire resistance is a curve. resistance = constant / area increasing the frequency higher, the current will be conducting through the surface of conductor, then jump into the… [cont.] Answered by Tony Q - Fri Aug 8 09:57:22 2008 From Yahoo Answer Search: "alternating current"  sustainablebusinessoregon.com Thu, 15 Jul 2010 19:19:48 GMT+00:00 Sustainable Business Oregon ... to efficiently convert the direct current produced by a solar panel system into the alternating current that is standard in American homes and offices. ...  offshore-mag.com Thu, 15 Jul 2010 14:19:43 GMT+00:00 Offshore Oil and Gas Magazine Power comes from Mongstad, north of Bergen, via a 9000 volt, 100-km (62-mi) long subsea cable that Statoil says is the world's longest alternating current ...  eurekalert.org Thu, 08 Jul 2010 19:06:37 GMT+00:00 EurekAlert (press release) ... liposome release the drug by making the shell leaky when heat-activated in an alternating current electromagnetic field operating at radio frequencies. ... From Google News Search: "alternating current"  opamp-electronics.com 370px x 545px | 23.80kB [source page] By measuring the period of the wave on the horizontal axis of the oscilloscope screen and reciprocating that time value in seconds you can determine the frequency in Hertz Voltage and current are by no means the only physical variables subject to variation over time Much more common to our everyday experience is sound which is nothing more than  alternatingcurrentdirectcurrent.com 400px x 400px | 57.70kB [source page] Are you at home wondering what a harpsical is Here s a basic idea of what one might look like From Yahoo Image Search: "alternating current"  solarwindreviews.com admin Sun, 25 Jul 2010 01:31:51 GM Alternatively, the electricity can be changed with an inverter, into . alternating current. to power electrical goods or it can be sold to the grid. Solar panels require light rather than direct sunlight to generate power, therefore, ...  make-energy.net admin Sat, 26 Jun 2010 21:26:56 GM How is . Alternating Current. (A/C) more efficient for long distance transmission of electrical energy? In mathematica terms?... Why is electrical energy transmitted in an . alternating current. rather than a direct current? ...  5magazine.wordpress.com 5magazine Wed, 14 Jul 2010 16:25:55 GM If you connected them to a power supply and applied a sinusoidal current an . alternating current. whose period is very regular then it would vibrate. And if you make it vibrate at audible frequencies and put it close to your ear, ... From Google Blog Search: "alternating current" |
