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Thread: Ohms/Infinity

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  1. #1

    Hmm

    Hello to all. I'm not clear on this two questions, please advise

    "0" ohm reading across a switch means switched is closed? True or false

    Infinity read across a switch means the switch is closed?
    True or False

    Please advise

  2. #2
    Join Date
    Apr 2003
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    469
    True
    "0" is a short

    false
    Infinity is an open

  3. #3
    Join Date
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    The way to think about it is that the ohm is a measurement of how hard electricity will have to travel to get across the path

    For example 0 ohms would be you getting across your living room
    Infinity is the same as you getting across the Atlantic with no boat

    So although a “0” even though it would actually have some resistance if measured with a good meter
    Would be closed
    Same as a draw bridge you can’t get across it if it is open and electricity can’t get across a switch if it is open

    Hope it helps and hope I didn’t insult you by over simplifying it

  4. #4
    If you are ever in doubt, touch your leads together and see what the meter says.

  5. #5
    Join Date
    Aug 2004
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    North Richland Hills, Texas
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    Originally posted by jultzya
    If you are ever in doubt, touch your leads together and see what the meter says.
    It is good practice, and could save your life some day, to switch your multimeeter to ohms and touch the leads together to check continuity through them every time you use your meter.
    If more government is the answer, then it's a really stupid question.

  6. #6
    Join Date
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    Roman

    Think of a switch like a draw bridge -

    When the drawbridge ( switch ) is closed - cars ( electrons ) can pass - The electrons from yur meter, for instance, passes through easily with very litle resistance - remembering that yur ohmmeter is looking for resistance - so very little resistance is close to none ( or zero )

    When the drawbridge is open - no cars can pass - neither can electrons though an open switch. Bcause no current can pass, using ohms law, there must be a very high resistance between the two points of the switch. The meter sees this 'open' as a very high resistance - too high for the meter to read & WaLa, the meter shows 'infinity' or 'overload'.

    Hope this helps and is not too confusing,
    Richard

  7. #7
    But is this true with both AC and DC electrical circuits ?

  8. #8
    Join Date
    Aug 2001
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    is there a diff between ac and dc circuits

  9. #9
    Join Date
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    yes ed there is
    one starts with an "A" and the other starts with a "D"

  10. #10
    Yes, AC stands for "alternating current"

    and DC stands for " direct current"

    I'm glad to see that there is a lot of talk on electricity here, I did some time in class on electrical stuff. So I may be able to help you out a little if you need it.

  11. #11
    Join Date
    Aug 2001
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    i thought it was the circuits that was being discussed not the titles

  12. #12
    Its like this Ed if we incorporate the whole ac dc theory into the draw bridge theory, it would come out something like this, when the draw bridge closes the cars
    ( electrons ) can pass to the other side. Which is fine, the difference is that if the cars are in a AC electrical circuit they will be changing lanes as they cross over the bridge ( weaving ) where as in a DC circuit they will cross the bridge in a single file line.

    Hope this makes it easier.

  13. #13
    Join Date
    Aug 2001
    Posts
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    changing lanes or direction of travel

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