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    Infinite Resistance

    I don't know if anybody's particularly interested in this, but.

    Another thread got me thinking about if V/R=0[zero]. When V is not zero.

    In other words no current flows from a voltage source with nothing connected across it.

    So to find the value of R, R=V/0[zero].

    So the divide by zero illegal function comes up. I've always prefered to think division by zero to equal infinity. Which would satisfy this equation (as it would many others). 1/(10 to the -23) is a big number.

    The smaller the divisor the larger the quotient. Until, reasonably, you reach X/0=infinity.

    The only problem I see is that infinity times zero is not a rational argument. But if that's the case why not put the illegal function there instead of at divide by zero?

    I know you're at least raising an eyebrow Charlie B.
    Sam, San Francisco Bay Area

    #2
    Re: Infinite Resistance

    physis,

    I think the mathematicians say that division by zero is undefined, that is, it is meaningless. However, there is also the matter of a ratio approaching a limit of infinity as the divisor approaches zero. Having said that, I think most wire twisters would say, "Who cares?", or "What does the code say?"

    The upshot of this is that you cannot compute the IR drop across an infinite resistance.

    [ December 06, 2004, 05:41 PM: Message edited by: rattus ]
    Don't mess with B+!
    (Signal Corps. Motto)

    Comment


      #3
      Re: Infinite Resistance

      Well rattus, hence line one.

      I've tried to find an answer that I would be happy with more than a few times but have never been satisfied.

      I think it's that the answer is always something like, the rules of convention dictate, blah blah. And it's been defined. Honestly I don't even remember the explainations anymore.

      It just seems the closer the divsor to zero the closer the quotient to infinity.

      The problem is that infinity is a concept that can't be given a rational value and therefore isn't math. But at the same time there's a similar situation with pi. It's an irrational number but we know it's real (not as an integer) because we understand the relationship it represents.

      Edit: Divide by zero and infinity, to me, seem to be a similar relationship.

      [ December 06, 2004, 06:00 PM: Message edited by: physis ]
      Sam, San Francisco Bay Area

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        #4
        Re: Infinite Resistance

        And how do we recocile no connection across a voltage source if we can't have infinite resitance?
        Sam, San Francisco Bay Area

        Comment


          #5
          Re: Infinite Resistance

          Physis, how close can you get to infinity? I say close enough. And for practical purposes, there is such a thing as an infinite resistance. But how would you color code such a resistor?
          Don't mess with B+!
          (Signal Corps. Motto)

          Comment


            #6
            Re: Infinite Resistance

            We use terms like infinite gain to describe an ideal OP amp and infinite impedence to describe radio circuits. It's almost common place in electrical engineering.

            how would you color code such a resistor?
            That's just it, it isn't a number. But I think you can say it's a value. So put that in your atom smasher.

            Edit: I don't think you can even color code .0001Ω

            [ December 07, 2004, 12:14 PM: Message edited by: physis ]
            Sam, San Francisco Bay Area

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              #7
              Re: Infinite Resistance

              You know, this reminds me of the attempt to reach the speed of light in a collider. The faster they accelerate ions, the more energy is required to get them going faster. The mass continues to increase towards infinity and the amount of energy goes towards infinity as more speed is obtained. It is impossible to get to the speed of light because the faster an object goes, the more mass it gains and the more energy it takes to accelerate it. The bottom line is that sub-light is the only possibility and warp one or greater ain't a gonna happen. Sorry, impulse power only to visit the stars.
              Charlie Eldridge, Indianapolis, Utility Power Guy[COLOR=red][/COLOR]

              Comment


                #8
                Re: Infinite Resistance

                Beam me up Charlie
                Wayne A. From: N.W.Indiana
                Be Fair, Be Safe
                Just don't be fairly safe

                Comment


                  #9
                  Re: Infinite Resistance

                  By Sam: Another thread got me thinking about if V/R=0[zero]. When V is not zero
                  Your right It's not v = 0 as it is I = 0
                  And this is the mathematical formula for a broken wire at a light switch.
                  Wayne A. From: N.W.Indiana
                  Be Fair, Be Safe
                  Just don't be fairly safe

                  Comment


                    #10
                    Re: Infinite Resistance

                    The mass increases to infinity at C and you can't do it because it takes infinite energy to accelerate an infinite mass. Some genious must have assumed we don't have infinite energy.

                    You can acheive I=zero with V=zero/R
                    Sam, San Francisco Bay Area

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                      #11
                      Re: Infinite Resistance

                      Infinity, for us practical types, is a number so large that we do not care anymore.
                      Don't mess with B+!
                      (Signal Corps. Motto)

                      Comment


                        #12
                        Re: Infinite Resistance

                        is a number so large that we do not care anymore
                        Hey I care when it still brings lightning down.
                        Wayne A. From: N.W.Indiana
                        Be Fair, Be Safe
                        Just don't be fairly safe

                        Comment


                          #13
                          Re: Infinite Resistance

                          Sam, before you go to bed tonight, have a nice warm glass of milk. Think sweet thoughts and try not to have nightmares again tonight.
                          Charlie Eldridge, Indianapolis, Utility Power Guy[COLOR=red][/COLOR]

                          Comment


                            #14
                            Re: Infinite Resistance

                            Hurk, even a resistor of infinite value has a voltage rating. You could wear a suit of chain mail tied to a code compliant ground rod to protect yourself from Thor and his thunderbolts.

                            Of course, the path followed by a thunderbolt has a rather low resistance. So just think big, like infinity squared or "e" to the infinite power!
                            Don't mess with B+!
                            (Signal Corps. Motto)

                            Comment


                              #15
                              Re: Infinite Resistance

                              Physis, drag out your math books and read about "indeterminate forms".
                              Don't mess with B+!
                              (Signal Corps. Motto)

                              Comment

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