Questions for those that believe in Electricity

by OnTheWayOut 52 Replies latest jw friends

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  TD

  Electricity is the force created when electrons, the negatively charged subatomic particles found in all atoms of the elements, move.

  Close. Electricity is the force which cause electrons to displace. (Charge) It is not a "flow" of electrons in the sense that grabbing a live wire means a gazillion electrons are "Flowing" into your body. --That would destabilize the atomic structure of a conductor. The copper windings in a generator are still copper regardless of how many decades its run and the copper atoms themselves still have 29 electrons each regardless of how much power its generated over the years. :-)
  
• 

  Twitch

  I believe in electricity, especially when it bites me...

  Though not exactly correct with respect to physics, I've found the water analogy the best in terms of understanding concepts and terms.

  Imagine a water tower. The water in a high tower will have more force when it hits the ground than a low tower. This is akin to voltage, a potential of energy

  Amperage is analogous to the diameter of pipe from reservoir to ground, a larger pipe allowing more water to flow through a point at a time, in effect.

  Power is essentially the energy that can be converted or spent doing something useful over time and is directly related to volts and amps. The same power could be had from a trickle from a very high tower (high V, low A) as from a low tower opened up wide (low V, high A). Applications may vary.

  And I've seen water towers, so electricity must exist...
• 

  Billy the Ex-Bethelite

  Looks like some of you have gotten "higher education". That makes Jehovah sad... just like plastic toy wizards.
  
• 

  GrreatTeacher

  E=I×R or Voltage = Amperage × Resistance

  and

  P=I×E or Power = Amperage × Voltage

  Just in case you ever wondered...the higher the voltage, the lesser the amount of amperage pulled (current), so if you run on 240 volts, your current is less than if you were running on 110 volts as is common in the US. We pull more current (amperage) because of the lower voltage and therefore we spend more on electricity.
• 

  TD

  ...the higher the voltage, the lesser the amount of amperage pulled (current), so if you run on 240 volts, your current is less than if you were running on 110 volts as is common in the US. We pull more current (amperage) because of the lower voltage and therefore we spend more on electricity.

  U.S. consumers pay for the wattage they use. We're billed in kilowatt hours.

  Voltage and Amperage are inversely proportional to each other in the triangle formula you've quoted above:
  

  You can see this relationship at work on the plate of a typical dual voltage motor:
  
  

  230 Volts X 14 Amps = 3220 Watts

  460 Volts X 7 Amps = 3220 Watts

  I'd wholeheartedly agree that higher voltages are more efficient in larger buildings with longer wiring runs, but that's why 277/480 is the de facto standard for large commercial buildings in the U.S.
  
• 

  GrreatTeacher

  Gotcha, TD. It's been a long time.

  I do know 277 is used for fluorescent lighting and it is deadly. If you get hit, it contracts your muscles so you can't let go. It killed a guy working on the lights in the room next to the gym when my son was in sports camp one summer. Very traumatic for the kids.
• 

  Twitch

  RE 277V

  I've heard from a friend in commercial renovations that this is the "widowmaker" voltage, for the mentioned reason.

  Then again, 50V or less could kill under the right conditions; all depends on the path of the current and the resistance between "contacts". A mere 20 milliamps can cause respiratory paralysis and 100 - 200 mA can cause fibrillation, should the current pass through the chest. Higher current may not necessarily cause the lungs or heart to stop but will cause severe burns likely internal, which ain't good.

  Or so it is written.
• 

  GrreatTeacher

  We used to test little 9v batteries by putting them on our tongue when we were little.

  If the toy wasn't working, we would pull the batteries out and lick them to see whether they were dead or not. No zing and we would just replace the batteries. But, if we got zinged, it was so sad because the toy was probably broken. :(
• 

  Bungi Bill

  OK - today I am in a rather pedantic mood, so here goes!

  Firstly, "Voltage" is a rather loose term that covers two closely rated phenomena:

  1) Electromotive Force (EMF) - which forms the "E" component of Ohm's Law (i.e. E = IR). This is the difference in potential energy between the two terminals of a complete electric circuit, and which produces the flow of electrons through it once the circuit is "closed".

  2) Potential Difference - which reflects the loss of potential energy across the various individual resistances within that same electrical circuit. This quantity is commonly referred to as "Volt Drop" and includes the energy loss in the circuit's conductors (which over a long run of cable, can be quite significant). Once often abbreviated to "PD", this is probably not a good idea anymore, as it could easily get confused with "Partial Discharge".

  The unit of measurement of both EMF and Potential Difference is the volt, and the sum of all differences in potential around an electrical circuit will always equal the EMF that has been applied across its terminals (whether from a battery, generator, transformer or whatever).

  Now we come to this quantity that some refer to as "amperage". Fellas, there is no bloody such thing as "amperage"! The quantity is known as "current", refers directly to the flow of electrons through an electrical circuit, and its unit of measurement is the ampere (usually abbreviated to "amp"). In other words, the amp is purely a unit of measurement - nothing else.

  In a hydraulic system, the total head of water would be the equivalent of the Electromotive Force (EMF) in an electrical circuit, flow of water (gallons per hour etc) would be the equivalent of an electrical current, and loss of head would be the equivalant of Potential Difference.

  As I said, I am feeling a little pedantic today!
  

  Bill.
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  GrreatTeacher

  Thanks, Bungi Bill!

  Current and amperage are used pretty interchangeably in the US, with amperage being the preferred term. But, I get your point that the amp is a unit of measure.

  May the Electromotive Force be with you!