Johnny, you are the guru of nitrous on this side of the pond. Your hands-on experience is second to none. Your problem solving skills and practical application of your hard earned knowledge (wisdom) has been demonstrated over and over. And I've only watched through this forum, and aspire to learn, learn ,learn.....
BUT,
What happens to the current in a wire or the water in a hose if there is no PRESSURE to push it? It goes to zero. What if there is pressure but there is no path to ground, or the end of the hose is plugged? Flow is zero. So, VOLTAGE is PRESSURE, and AMPERAGE is FLOW. (That fancy term 'emf' is 'Electro Motive Force', another term for voltage, and is the force or pressure that makes electrons move. (See link:
http://www.ndt-ed.org/EducationResource ... oltage.htm ) When electrons move, we want to know how many are moving by in a given time frame, and amperage is based on Coulombs per Second, a measurement of how much electrical charge has passed by. (See link:
http://www.ndt-ed.org/EducationResource ... perage.htm ) This Ohm fellow was very smart. When he devised his formula for the relationship between voltage and current {even the term current, like the current in a creek, infers flow...} in a resistive context with Direct Current, the unit Ohm got set as the resistive value which will allow 1 Ampere of current to flow when 1 Volt of electrical pressure is applied. )
Your practical conclusions don't seem to be swayed by your inverse perception of this reality, but there can be no doubt about which one is the Creator of the Motion, Pressure/Voltage, and which one is doing the Moving because of it, Amperage/Flow. Just like water, or gasoline in our fuel feed lines, if you have 12 pounds per square inch of fuel pressure, you can have anything from zero flow with infinite resistance, plugged line, through to maximum useable flow with 12 lbs maintained by changing the resistance of the path, or how much fuel is let by in a given time, or maximum unrestricted flow which will mean in this case that the pressure will go down to match the highest possible flow to the very low resistance created with the 'un-natural' setup of an open ended pump. (This could be related to circuits that are considered 'current limiting', but that's another matter.)
Actually, Direct Current of any voltage sufficient to create current through your body is dangerous because direct current is constant flowing, so once going, it has no 'reason' to stop, unless the voltage is removed somehow. Alternating Current, AC, used in all our buildings is safer at high voltages since it alternates polarity 120 times every second, so there is a portion of the time when there is no current flowing and a person can 'let go' of the voltage source. What kills you is a relatively low current that flows right through your heart, so if you have a circuit from your left arm to your right leg, its going to go right through your heart. Even from arm to arm is dangerous, but it could travel slightly above your heart. Our bodies have fairly high resistance, so it takes a fairly high voltage to get a current flowing in us, but our sweat, being salt water, helps conduct electricity.
Alright, enough Electrical Principles 101... And I just saw your next post. I think the simple explanation is that you got it, yes, but got it in reverse when you restate it, but when you apply it, you're doing so correctly, if that makes any sense. Interesting you mention high school, since I found those two links above on an educational site.
You're still my nitrous hero, Johnny!
Bart