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A Question about Parallel Resistances

  1. Oct 15, 2013 #1
    Hello Guys !!

    My question is : why in these photos the ohmmeter reads the total resistance ??



    I mean why in (a) the ohmmeter can't read the 8 ohms resistance ?


    Why in (b) the ohmmeter can't read the (2||10 ) resistance ?

    Thank you Guys !! :))
  2. jcsd
  3. Oct 15, 2013 #2


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    If you want the resistance of a component you often need to disconnect it from the circuit.

    In this case the connections for the ohmmeter in (a) would give the same reading if you slid the contacts along the wires to a position as shown in (d).
  4. Oct 15, 2013 #3


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  5. Oct 17, 2013 #4


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    If there are many paths for current to take then it will take them. The meter just measures the amount of current that it supplies from its internal source of volts and does the Sum R = V/I. It can't know which portion of the current is going through which resistor. So you need to measure each resistor separately. This will involve disconnecting one end of the other two. (You needn't disconnect both ends.)
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