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Question on ohm's law

  1. Jul 18, 2015 #1
    according to ohm's law, the current is proportional to the potential difference provided that the temperature remains constant. so , the for equation , R= V/I, may i know which is the constant in the equation? i know the general form of direct proportion is y=kx or y/x=k but in R=V/I, i am unable to identify which is the constant. please help me with this. thank you
  2. jcsd
  3. Jul 18, 2015 #2


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    hi there

    There is no constant in there other than whichever one you want to remain constant

    so for your example R = V/I ... if V is steady and you measure the current flowing in the circuit, you can establish the resistance present
    so for any variation of those 3, from any 2 knowns, you can work out the unknown value

  4. Jul 18, 2015 #3


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    Why would the temperature need to remain constant? Resistance will vary with temperature but that doesn't invalidate Ohm's Law, it just means that for a fixed voltage, the current will fluctuate inversely with the resistance fluctuation
  5. Jul 18, 2015 #4
    Ohm's law states that for constant physical conditions , the potential difference applied across a circuit is directly proportional to the current induced .

    Or , V ∝i , and V=iR .

    Thus the constant of proportionality , by ohm's law , is R .

    I hope this helps .
  6. Jul 18, 2015 #5


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    OR, the current induced is directly proportional to the voltage applied.
  7. Jul 18, 2015 #6
    it does make sense to me....my notes states so as well but i just needed clarification
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