More specifically, I understand what they are (Voltage is the guide of electricity and Current is the speed of the flow), but I’m having trouble understanding their relation. For example: in a hypothetical scenario where I have a 220v source that outputs 1amp through an uncovered wire, since the voltage is only the guide of electricity, would it be safe to touch?
I also may be wring about the definition of Voltage and Current all together.
All help is appreciated! THX!
(I’m 14 and learing about electronics on the internet. English is also NOT my first language)
In: 5
Voltage means how much the electricity wants to flow. How strong the ”push“ is. It also exists without a circuit.
Current means how much electricity flows when you have some kind of circuit.
You can visualize very good with pipes and water. It is the same principle.
The way I understand it and think of it is this.
We measure electricity in different ways.
Think of volts like how much pressure is behind it, think of amps as how much volume is available, and the ohms is the measurement of resistance.
Watts is a relation of Amps x Volts and is used to measure consumption.
Look at a house in the US. The electrical outlets in say the bedroom are typically 120v/15A circuits. If I plug in an alarm clock, it is designed to operate at 120v of pressure, but consumes very little capacity (0.1A) making it only consume maybe 12W of the total 1800W provided on that circuit.
To break it down with a plumbing analogy. A bedroom circuit might be a kitchen faucet. The line from the meter might be a garden hose (same pressure, more volume), a high power line by the road might be a fire hose (high pressure high volume), a taser might be like a power washer (super high pressure, very little volume).
And consumption is measured in watts (GPM). Since 12v @ 1A = 12w and 1v @ 12A = 12w. It’s like getting the same gallons per min out of a small hose at higher pressure as a larger hose at lower pressure.
Hope my ramblings don’t confuse you more.
The Voltage *U* is the electric potential.
You can make an analogy with a waterfall.
When water reaches the top of the waterfall, it has a lot of *potential energy*. That energy will be converted to *kinetic energy* (which is tied to speed) as it falls down.
Voltage is the same, but it’s the potential energy of electric charges.
The Current *I* is like the flow of your waterfall: how much water goes through it.
So Voltage is always measured between two points. You need to know how high your waterfall is in regards to the bottom of it.
Imagine you have a long rectangular tub of water, that you can tilt back and forth. If you raise one end really high, all the water flows quickly to the other end.
Voltage is how high you raise one end and current is how much water is in the tub.
So a high voltage and low current means a little water moving fast and a low voltage and high current means a lot of water moving slowly.
You know how molecules diffuse (i.e tend to move from a higher concentration of particles to a lower concentration)? Well, the concept of diffusion in molecules is similar to voltage of charged particles. The great change in energy between regions on a circuit is what rapidly encourages charged particles to flow. Current is like the measurement of the time taken for an amount of charge to flow through a complete circuit once.
You’re missing two more concepts — resistance and work. When you put voltage, resistance, and current together they produce work, and you have the basics of electricity.
A useful analogy is a waterfall on a river. Voltage is the height of the waterfall. Current is the amount of water flowing over the waterfall. Resistance is how narrow the channel is that leads to the waterfall. Work done by the electricity is how much force ends up hitting the rocks at the bottom of the waterfall.
Compare two waterfalls, one taller than the other. The taller one represents a higher voltage. If the both have the same amount of water flowing through, the taller one will do more work. Or, to look at it another way, if you want to get the same amount of work from the two waterfalls, the shorter one will need to have more water flowing over it (i.e., higher current).
This is why in a country with 125 volt electrical systems an electric kettle will take more time to boil water than the same electric kettle in a country with a 240 volt systems. The mechanism in the electric kettle can only sustain so much current, but that same amount of current coming from a 240 volt system does more work than from a 125 volt system.
Resistance determines the amount of current flowing through. If there is only a narrow stream leading to a waterfall (i.e., high resistance) then only a small amount of water will flow through. This limits the amount of work that can be done. If there was a wider channel (lower resistance) leading to the waterfall then more water could flow through (higher current) enabling more work to be done.
To address your last question, first things first: DO NOT TOUCH LIVE ELECTRICAL WIRES!!!!! It doesn’t matter whether you’re on a 125 v or 240v system, both are dangerous. To go with the waterfall analogy: it doesn’t matter if the waterfall is 125 meters tall or 240 meters tall. If you jump off of either one you’re going to be dead. It’s just a question of how hard you will hit and how much of a mess you will make at the bottom. Height here is a reasonably good analogy: 12 volts (like from a battery) is generally safe; even a relative novice can jump off a 10 meter diving platform into a pool safely with only a little instruction. Jumping from a 25 meter height into water will likely get you hurt, just like the 24 volt system on trucks can be dangerous. 125 or 240 volts? Don’t do it!
In electrical terms, your nerves function on voltages in the millivolt range and currents in the milliamp range. Household electrical systems are literally 1000x as powerful. That amount of difference ***will*** unalive you in a big hurry.
It’s not a perfect analogy; in some ways a set of rapids along a river is a better analogue but it’s harder to explain.
There’s a lot more to understanding electricity, both from a theoretical side and from a practical side. Hopefully this helps get you started.
Edit: hit post accidentally before I was done.
If electric circuit / battery was a waterfall, then the voltage is the height of the waterfall (how much potential there is for water to fall) and the volume of water flowing Is the current.
You can have a high waterfall (high voltage) but very little water flowing (low current) or the other way around, or lots of both, or not much of both.
>I have a 220v source that outputs 1amp through an uncovered wire, since the voltage is only the guide of electricity, would it be safe to touch?
A voltage source doesn’t provide a fixed amount of voltage and current. The amount of current depends on the resistance that is connected. Look up Ohms law and how to use it.
>would it be safe to touch?
A high voltage hurts, but current kills. Only about 300ma (milli amp) passing through the heart is enough to kill. How much current passes through your body depends on the resistance of your body. It’s normally very high (kila ohm), but depends on the path
For the sake of explanation, I’m going to make analogies to water flow.
Voltage is a difference in potential. You might think of this as elevation. Current is the amount of flow. You can think of this as the speed of a river.
For a low difference in voltage (like a very gentle slope, almost flat), there won’t be much current (water moves slowly). For a high difference in potential (high elevation to low), there is more current (like a waterfall).
There are other factors which play into this, but that serves to generally illustrate the relationship between voltage and current.
I like the water hose analogy. The water is the current, the water pressure is the voltage, and the size of the hose is the resistance. More pressure (voltage) means more water (amps). Less resistance (think fire hose vs garden hose) means more current.
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