7 ms·

Can you share what helped it click? I’m in the same boat, trying to understand it through analogies.

carapace 4y ago
These are physical properties that can be experienced (although there is some risk) for voltage you can touch a Van de Graaff generator, for current you can touch a battery to your tongue. That's the way to understand electricity without analogies. :) Anyway, voltage is always measured between two points (one is typically called "ground" but that's not important here.) It's a difference. (A difference of what? No one knows. That's just the way it is.) Current is always measured through a single point. It's a count of the charge flowing past a point per time unit. (What is charge? No one knows. "Charge" is just a name for the mysterious something that "voltage" is a difference of...) When electricity moves it obeys a (very simple) Law called (Ohm's Law) e.g.: E = V/R The current (E) is the Voltage divided by the Resistance. E.g. is I have a 5 Volt power supply and I put a 100 Ohm resistor across it (remember that voltage is always between two points) then 5/100 Amperes of current will flow through it. Also, If I take just the resistor and drive 0.05 Amps through it, it will develop a voltage of 5 volts, as measured from one end of the resistor to the other end. Now if that doesn't help you, remember the advice of John Von Neumann to Felix Smith: "Young man, in mathematics you don't understand things. You just get used to them."
- _dain_ 4y ago
  >Current is always measured through a single point. It's a count of the charge flowing past a point per time unit. (What is charge? No one knows. "Charge" is just a name for the mysterious something that "voltage" is a difference of...) I think you're being overly mysterious here. It's the number of electrons passing through the wire per second. And charge isn't the thing that voltage is a difference of; it's potential difference, as in electric potential energy. The "water in a pipe" analogy really isn't that bad; it's gravitational potential instead of electrical potential, and amount of water instead of amount of electrons.
  - carapace 4y ago
    > I think you're being overly mysterious here. Maybe, but I feel electricity is mysterious, eh? I mean, we don't know what it is, nor why the Universe has it, and we aren't likely to ever figure it out, eh? Really that's all I was trying to point out with that: we know how electricity behaves but we don't know what it is. Sometimes people get hung up on that. In any event, I usually recommend William Beaty's 'What Is "Electricity"?' http://amasci.com/miscon/whatis.html http://amasci.com/miscon/whatis.html

These are physical properties that can be experienced (although there is some risk) for voltage you can touch a Van de Graaff generator, for current you can touch a battery to your tongue. That's the way to understand electricity without analogies. :) Anyway, voltage is always measured between two points (one is typically called "ground" but that's not important here.) It's a difference. (A difference of what? No one knows. That's just the way it is.) Current is always measured through a single point. It's a count of the charge flowing past a point per time unit. (What is charge? No one knows. "Charge" is just a name for the mysterious something that "voltage" is a difference of...) When electricity moves it obeys a (very simple) Law called (Ohm's Law) e.g.: E = V/R The current (E) is the Voltage divided by the Resistance. E.g. is I have a 5 Volt power supply and I put a 100 Ohm resistor across it (remember that voltage is always between two points) then 5/100 Amperes of current will flow through it. Also, If I take just the resistor and drive 0.05 Amps through it, it will develop a voltage of 5 volts, as measured from one end of the resistor to the other end. Now if that doesn't help you, remember the advice of John Von Neumann to Felix Smith: "Young man, in mathematics you don't understand things. You just get used to them."

_dain_ 4y ago
>Current is always measured through a single point. It's a count of the charge flowing past a point per time unit. (What is charge? No one knows. "Charge" is just a name for the mysterious something that "voltage" is a difference of...) I think you're being overly mysterious here. It's the number of electrons passing through the wire per second. And charge isn't the thing that voltage is a difference of; it's potential difference, as in electric potential energy. The "water in a pipe" analogy really isn't that bad; it's gravitational potential instead of electrical potential, and amount of water instead of amount of electrons.
- carapace 4y ago
  > I think you're being overly mysterious here. Maybe, but I feel electricity is mysterious, eh? I mean, we don't know what it is, nor why the Universe has it, and we aren't likely to ever figure it out, eh? Really that's all I was trying to point out with that: we know how electricity behaves but we don't know what it is. Sometimes people get hung up on that. In any event, I usually recommend William Beaty's 'What Is "Electricity"?' http://amasci.com/miscon/whatis.html http://amasci.com/miscon/whatis.html