Question about the workings of alternating current

[electricDesire]

the question is about alternating current!! AC means the electrons move backward and forward across the wire. now if we connect the wire between terminals of a generator, the electrons would move backward and forward, then how it could reach the other terminal of the generator. forward then backward then the same previous forward then the same previous backward! then how do they move?

 

[FvM]

Re: AC

They don't move actually very far within a half-cycle.

 

[fsahmed]

Re: AC

The electrons simply oscillate between the two terminals

 

[electricDesire]

Re: AC

physically, they go forward and backward no oscillation. current and voltage oscillate. any explination?

 

[laktronics]

Re: AC

Hi,
The electrons do go around the circuit for each instantaneous value of the applied voltage, and do reverse their direction of flow, when the applied voltage is reversed. If it does not happen for each instant, you would have found discontinuities of current and voltage around the loop and you should have to place fuses and induction coils at specific locations of the loop only, which obviously is not the case.
Regards,
Laktronics

 

[Jone]

Re: AC

Take for example a light bulb. It is basically a very thin wire. Electrons moving through a thin wire will collide into each other and other particles more frequently than in a thick wire because there is less space. As the electrons collide, energy is lost (which turns into heat). Or we can say that the work is done is the voltage drop. Now it doesn't matter if we have an AC or DC current; pulling charge back and forth produces the same effect as DC. So it is the movement of the charges that is the cause, not that they have to go all the way around.

 

[laktronics]

Re: AC

Hi,
Unless the electrons moved in the outside wires connected to the bulb how come an ammeter connected in the loop shows a current?If the electrons were restricted only to the bulb filament then the ammeter should have shown zero current.
Regards,
Laktronics

 

[Kral]

Re: AC

electricDesire,
Here's a (Somewhat simpleminded) analogy: Visualize a cardboard tube filled with billiard balls. The billiard balls represent electrons. Insert another ball in one end of the tube. All the balls move a distance equal to the diameter of the billard ball. The ball you inserted never reaches the end of the tube. However, the effect of inserting the ball is seen by the motion of the last ball in the tube.
Regards,
Kral

 

[Jone]

Re: AC

Hi,
Unless the electrons moved in the outside wires connected to the bulb how come an ammeter connected in the loop shows a current?If the electrons were restricted only to the bulb filament then the ammeter should have shown zero current.
Regards,
Laktronics

Of course they move back and forth by the same amount in the wire too. It's like pulling a thread back and forth through a hollow tube. At the place were the tube is thin the pulling makes the tube warmer because of the friction between the tube and the thread. It doesn't matter if the thread is pulled in the same direction all the time, or if it is pulled back and forth. The effect is still the same.