Please explaine D.C. & A.C. circuits,current?

Question

Please explaine D.C. & A.C. circuits,current?

Answer 1

Lets get the answer in a simple and efficient manner.

The basic difference b/w dc & ac current is frequency. you can simply understand frequency as a measure of fluctuations of current b/w a +ve & -ve value over a period of time. Direct current, as the very name suugests, has no frequency and its value remains constant over any period of time. But ac fluctuates b/w a +ve & a -ve value.

Talking about circuits, the basic difference is that a capacitor blocks ac while a resistor blocks dc.

Hope your concept got cleared,

Shanky

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Answer 2

Okay, as for current, its funny but scientist started the convention that current flow from positive to negative ends, when in actuallity, the electron difference shows that more electrons are in the negative end and they travel to the positive.  Think in it this way:

+ ----current-----> -

DC circuits and AC circuits in regards to current are pretty similar.  V=i*R holds true, but in a different sense.  In DC circuits you will have a 1 steady voltage, lets say 12V and a resistor of say 6 ohms.  that gives  a current of 2 Amps.  This current will remain constant until the 12 volt souce is shutoff.  With AC, you have a sinusoidal voltage.  Your source may be a 120V wall jack, but that doesn't mean you get 120V all the time.  It fluctuates with a frequency in accordance to the its angle...  a little more than I can type out for you, that I am sorry.  The biggest difference in AC circuits is that V=i*Z where Z is the impedence of the circuit.  Impedence is the combined value of all the resistive elements of the circuit(i.e. resistors, inductors, capicitors).  This is only instanteous.  There are MANY different equations to find the correct current, but for an introduction this should do.

Answer 3

'Electricity flows in two ways; either in alternating current or AC and in direct current or DC. The word electricity comes from the fact that current is nothing more than moving electrons along a conductor, like a wire, that have been harnessed for energy. Therefore, the difference between AC and DC has to do with the direction in which the electrons flow. In DC, the electrons flow steadily in a single direction, or "forward." In AC, electrons keep switching directions, sometimes going "forwards" and then going "backwards." The power that comes from our wall outlets is AC, the more common, efficient kind.'