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Homework Help: Physical explanation of VI

  1. Jul 27, 2017 #1
    1. The problem statement, all variables and given/known data
    Please provide a physics explanation of this question:
    How does load current affect the potential difference across the terminals of a cell?

    2. Relevant equations

    3. The attempt at a solution
    p.d. inversely proportional to current. Thus, when I increase, the p.d. decrease and vice versa

    Is this a good enough 'physics explanation' for this question? Thanks~
  2. jcsd
  3. Jul 27, 2017 #2


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    No, it is not because in an ideal power source it is not true so you need to explain why it IS true (and preferably also to what extent it is true) in a real power source.
  4. Jul 27, 2017 #3
    I don't know why is it true... :sorry:
  5. Jul 27, 2017 #4


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    An ideal cell maintains terminal voltage independent of load current . In a real cell the terminal voltage drops as load current increases .

    What common electrical component could you put in series with an ideal cell so that the ideal cell and the additional component together behave like a real cell ?

    Edit : Haven't you essentially got the answer to this question in your previous posting?

    Last edited: Jul 27, 2017
  6. Jul 30, 2017 #5
    Voltage times current gives power, but to answer this question, you'll need Ohm's Law.
  7. Jul 30, 2017 #6


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