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# What is the difference between amperage and voltage? ###### 2015-12-17 04:19:40

Amperage, or current, is a measure of the amount of electrons moving in a circuit.

Voltage is a measure of how much force those electrons are under.

In a circuit, say a light and switch in your home when the light is on there there is a voltage across the filament of the bulb that is pushing amperage through the circuit.

When the switch is off there is voltage across the switch but there is no current flowing because it is "blocked" by the switch.

An analogy that normally helps to illustrate the difference between voltage and amperage:

you have a garden hose, the nozzle is closed. You've got pressure but no flow-voltage but no current (amperage). Open the nozzle and the pressure in the hose causes the water to flow - turn on the light and the voltage causes the current to flow (amperage)

Answer (in understandable terms)Voltage is how much electricity there is.

Amperage is how fast that electricity is moving (if at all).

There are other things involved in electricity, electrical currents, etc., but this question is about amperage ("amps") and voltage ("volts").

Here's a good analogy. Imagine you have a bucket and a regular watering hose. The hose is connected to a spigot, or spout(which is the thing where you turn the water on and off by twisting the little handle), but the water is 'turned off' at the moment. And although it is 'off,' it could easily be turned back 'on' by twisting the handle and allowing the water to flow out. Also, the more you twist, the more water comes out.

Don't worry -- this will all tie together. :)

If there was no spigot then water would be flowing out all over the place, all the time (until there was no more water), because there'd be no resistance to block it from flowing. That being said, when you're done using a hose and you go to 'shut the water off' (by tightening the handle on the spigot), what you're actually doing is forcing the water to stop flowing because when the handle gets tighter, on the other end of the handle is a little piece of metal that gets forced into the pathway of the water-flow, which in turn restricts how much water can come out; if you tighten the handle all the way, the little metal thing will be completely blocking any water from flowing out -- when the water stops coming out, you've officially 'shut the water off.'

Likewise, if you want to fill your bucket up with water, you'll need to turn the water on, which you accomplish by twisting the handle in the other direction. This, in turn, moves the metal thing away from blocking the water, resulting in a flow (of water) into the hose. Now, you can use the hose to point the water so that it flows into the bucket. And, the more you loosen the handle on the spigot, the more water comes out at once.

This is basically the how amperage & voltage work. Like it says above, voltage is how much -- amperage is how fast. And again, if there was no 'spigot-metal-thingy-blocker' to get in the way, water would be flowing out everywhere; and if you shut the water off, using the 'thingy-blocker,' water stops flowing. Either way, regardless of whether the water is on or off, 'how much' water there is sitting on the other side of the spigot doesn't change(unless you forget to pay the water bill). The same is true for voltage -- the number of volts doesn't change.

What does change is the "rate of flow" -- aka "how fast it's flowing." Amperage can be defined as exactly that: the rate of flow (or current). You can have all the water ('voltage') in the world but if it's not flowing (because the spigot is shut off), and therefore the rate of flow ('amperage') is 'zero,' you'll NEVER fill your bucket (Try it! Put a hose in an empty bucket, and don't turn the water on -- I'll bet you'll find that the bucket stays pretty dry). :)

Ultimately, to sum up, you can think of it like this:

• Voltage is useless without amperage. If it's just 'sitting there' then it's probably not doing much of anything that would benefit you.
• Amperage 'doesn't exist' if there's no voltage. How can there be any rate of flow if there's nothing flowing in the first place?

Now (if you haven't fallen asleep already), maybe (hopefully) you can figure out / understand why & how it is that a smoke detector uses a 9-volt battery, while a car uses a 12-volt battery (not much difference), and-- well, you get the point.

There is a water source like a lake, the lake flows into a river, and there is a dam at some portion of the river and then there is at the end of the line the ocean.

The lake is the source or (Service Connection 120/240) The river is the current (amperage) the dam is the (switch), and the boulders, ravines, and sandbars are restrictions of the flow of water which is (Ohms -Resistance)the ocean is then the end of the line.

another answer for the mechanically minded

this is not exactly a true representation and can be construed as the wrong forces in motion but for a releationship diagram it depicts the hierarchy and extent each principal has on each other.

in a internal combustion engined car

voltage is like horsepower in a car this is all the energy available to do work

amperage is the accelerator... how much power that can flow at a given moment

gearbox is like a transformer.

## Related Questions The relation between amperage and capacitance is that amperage is equals to capacitance times the rate of voltage change over time. This voltage refers to instantaneous voltage. Voltage is the "pressure" of electricity, whereas amperage (current) is the "flow" of electricity. Voltage can be present without amperage (at a switch in the off position), but amperage can not exist without voltage. Once you flip the switch and the light turns on, you now have amperage. Voltage is measure in volts (E). Current is measured in amperes (I). Related terms would be Power and Resistance. Power (P) is measured in watts. Resistance is measured in ohms (R). P = I x E E = I x R Amperage is the measure of electrical current, which is the measure of the electron flow through something (like a wire). The more electrons that flow through the wire, the higher the amperage. Current is understood as moving from higher voltage to lower voltage but since electrons are negatively charged, they actually flow in the opposite direction.Voltage is a measure of electrical potential between two items. The electrical potential can be looked at as the difference in the electrical charge between two items. The item with more negatively charged electrons has a lower voltage. This doesn't make sense, "current" is "amperage" so the higher the voltage the lower the amperage, and the lower the voltage the higher the amperage.

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