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Kanse
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How would Voltage & Current relate to a garden hose? I know that the pressure of the hose is Voltage and the flow of the hose is current but I need more details about it.
No, you can't. Voltage is a pressure and is directly analagous to mechanical pressure. This is not an uncommon analogy for a teaching aid because it is exactly the same mathematically: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir.htmlAgnostic said:You can think of voltage as the amoutn of energy to move an electron through a resistance
russ_watters said:No, you can't. Voltage is a pressure and is directly analagous to mechanical pressure. This is not an uncommon analogy for a teaching aid: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir.html
As you can see:
pressure = voltage
volume flow rate = amperage
resistance = resistance
Who?cyrusabdollahi said:He's correct.
I suppose that is a rhetorical question, but it is often very useful to cross back and forth between mechanical and electrical energy. It may not be as direct, but I use the concept regularly when figuring out things like fan or pump efficiency or cross-checking electrical and mechanical energy via efficiency: a joule of pump energy and a joule of electrical energy are the same thing and you can go backwards all the way from flow rate and pressure to kw and voltage and amperage.What are the units of a volt?
Then again, why do we need to make an analogy between electricity and water systems. Its totally useless. It was never worth a damn for anything other than showing there was an analogy.
Maybe not, but I've seen the analogy taught in both directions in school. For people who can't understand one, relating it to the other, if only for 15 minutes when first learning it, can be helpful.I never did a single circuit problem saying, soooo if I think of the pressure through the inductor.....
Agnostic said:You can think of voltage as the amoutn of energy to move an electron through a resistance
and current as how many electrons are moving through the resistance.
I suppose that is a rhetorical question, but it is often very useful to cross back and forth between mechanical and electrical energy. It may not be as direct, but I use the concept regularly when figuring out things like fan or pump efficiency or cross-checking electrical and mechanical energy via efficiency: a joule of pump energy and a joule of electrical energy are the same thing and you can go backwards all the way from flow rate and pressure to kw and voltage and amperage.
cyrusabdollahi said:This analogy business is not necessary. [..] I don't need to know anything about pumps, water, or pressure to understand what's going on, and I avoid falling into traps by drawing too close an analogy with mechanical systems. Electrons don't have turbulence, water flow in pipes do, this is the danger of analogies.
cyrusabdollahi said:I don't understand why people can't just accept voltage, current, and resistance for what it is. Like I said, you apply a voltage to a resistor, and you get a current. Cause leads to effect. There is no need for any analogies here. These are the physical observations of the system. I don't have to go through analogies just to explain what I am seeing before my own eyes.
You don't need an analogy for water systems, you accepted that for what it was. Similarly, you should accept voltage, current and resistance for what it is. There is a difference in potential. The charge moves in response to that change in potential. You get current. It is what it is.
So, current, for an inductor, LAGS behind voltage since sint lags behind cost by 90...the opposite holds for a capacitor.
cyrusabdollahi said:What do you mean one does not cause the other?
Get a battery, plug the ends onto a resistor. You will get a flow of current through the resistor.
You just applied a voltage to the resistor. The effect is you see a current. What does phase have to do with anything? I never said an AC source.
Ok it lags, fine. Does that mean you get a current before you applied a voltage to the system?
cyrusabdollahi said:No, its not.
You mean to tell me, you can't decide if you pluged in your circuit to a voltage supply, or it magically ran current through itself?
You *had* to plug it in at some point in time.
Charge simply won't move if there is no potential difference.
leright said:MY point was voltage does not always CAUSE current.
Cyrus said:I don't understand why people can't just accept voltage, current, and resistance for what it is. Like I said, you apply a voltage to a resistor, and you get a current. Cause leads to effect. There is no need for any analogies here. These are the physical observations of the system. I don't have to go through analogies just to explain what I am seeing before my own eyes.
You don't need an analogy for water systems, you accepted that for what it was. Similarly, you should accept voltage, current and resistance for what it is. There is a difference in potential. The charge moves in response to that change in potential. You get current. It is what it is.
True of course.cabraham said:The trouble with analogies is that they are only partially equivalent. A current in a wire is surrounded by a magnetic field. If the field is time changing, & another circuit is in proximity, induction takes place. Fluid flow does not exhibit this "transformer behavior".
Voltage is a measure of the electric potential difference between two points in a circuit, while current is the flow of electric charge through a conductor.
Voltage is analogous to the pressure in a garden hose. Just as higher water pressure causes water to flow faster and with more force through a hose, higher voltage causes electric current to flow faster and with more power through a circuit.
The relationship between voltage and current is described by Ohm's Law, which states that the current flowing through a conductor is directly proportional to the voltage applied to it and inversely proportional to the resistance of the conductor.
Current is analogous to the flow of water through a garden hose. Just as a larger diameter hose allows for more water to flow through it, a higher current allows for more electric charge to flow through a circuit, resulting in a stronger and more powerful flow of electricity.
The main factors that can affect voltage and current in a circuit are the resistance of the conductor, the type of material the conductor is made of, and the amount of energy being supplied to the circuit. Other factors such as temperature, length of the conductor, and the presence of other electrical components can also impact voltage and current.