Since charge is conserved why is there no return?
2007-01-30 08:51:34 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The flow of electricity (electrons) is analogous to the flow of water (water molecules). Your home is likely wired for alternating current which means that the electrons flow to and fro changing direction at 60 cycles per second. When the power plant pushes electrons into the wire the effect is felt at your house at nearly the speed of light although individual electrons move through the wire relatively slowly depending on how much current you are drawing. Thus electrons are pushed into your house, through your light bulb (etc.) and into the ground through grounded wiring then they are pulled back from the ground, through your light bulb (etc.) and back toward the power pole. It would be like a piston water pump pushing and sucking water through a pipe.
2007-01-30 09:37:29 · answer #1 · answered by Kes 7 · 1⤊ 2⤋
It tries to. The electrons try to go back to the power plant but before they get very far, the alternating nature of the AC power turns things around so they start going the other way.
But let's simplify the power. Let's say it's DC power. In this case, the electrons do get back to the power plant. It would be 2 wires, Hot and Neutral, same as with AC power. (Plus there is the safety ground which isn't part of the power distribution. It's there for a different reason.)
The electrons would come to your heater on the hot lead, pass through your heater generating heat, and from there would return to the power plant on the neutral lead. It's a loop: hot line, heater element, neutral line. The electrons can't get off that loop. When they have passed through the heater they have to keep moving because there are more electrons coming out all the time. What happens if someone reaching the end of an busy escalator stands still at the end?
2007-01-30 09:25:29 · answer #2 · answered by sojsail 7 · 0⤊ 0⤋
POWER DOES NOT GO TO THE EARTH! You are not paying for power you are paying for energy.
The energy is being used to to move a charge from point a to point b. These points a and b could be as close as adjacent atoms.
By shorting your circuit to ground you are forcing all available energy to dissipate across the largest resistor. That resistor is usually the contact between the hot wire and ground. I guess this is why the sparks are flying. So it is best to run the current in some useful machinery.
The power however is the rate of energy used.
Again you are paying kilowatt hours. Right ?That is energy. (E=P t)
So the charge contained within a conductor is always the same and therefore stays conserved. On the surface of the conductor is a different story ;-).
2007-01-30 09:08:03 · answer #3 · answered by Edward 7 · 0⤊ 0⤋
I'm not sure if you mean 'go to the earth' because your house electrical system is grounded... This is no provide a safety measure, as well as maintain the zero reference level.
You are right that charge is conserved, when you use electricity you are affecting the current level flowing through the power lines... And in essence you are connected back to the power plant.. Everyone is connected together (at least on their 'grid') so if everybody tried to draw too much current, the system fails either catastrophically (like blowing a transformer), or partially like a brown-out where the current demand is too high for the system to keep the voltage at the right level (100-130V in North America).
2007-01-30 08:58:46 · answer #4 · answered by Leonardo D 3 · 0⤊ 0⤋
Actually, there is no power from your home to the earth. Rather your home uses up the power from the power plant by converting it to other useful modes.
The charge in operation here is such that it builds up a potential difference (say 240V) in a plant that can handle the current demand of your home.
So throughout the power plant operation, charge is conserved in that the required potential difference (voltage) is maintained.
2007-01-30 09:11:23 · answer #5 · answered by agboola f 2 · 0⤊ 0⤋
Think of electricity as water and the wires as piping. You can only go one way. When it's used it is consumed by the devices it is attached to, for heat, light, motors, etc. Electricity is not entirely efficient. A ground wire is used to prevent electrical charges from building up, and is not the 'sewer pipe' for electricity.
2007-01-30 09:01:42 · answer #6 · answered by MarauderX 4 · 0⤊ 1⤋
because ground is 0 voltage... and the current tends to take the lower voltage possible.
and because in the plant is created the current (electrons are made)... and the ground in +...and the movement of the electrons is the current.
2007-01-30 09:00:12 · answer #7 · answered by ddroxana 2 · 0⤊ 1⤋