Power, Resistance Conversation Problem

Discussion in 'Physics & Math' started by Saith, Sep 7, 2006.

  1. Saith Registered Senior Member

    Messages:
    149
    This should be easy. But Im having problems.

    I am making a table to convert between power, pressure, current and resistance. There seems to be discrepencies in 4 places though. It looks like there is some problem with the relation to power and resistance. But I can't figure out what it is.

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  3. James R Just this guy, you know? Staff Member

    Messages:
    37,791
    "Pressure" is not the right term. The correct term is "potential difference", or "voltage" if you like.

    The relevant equations are:

    P = VI
    V = IR

    where P is power, V is voltage, I is current and R is resistance.

    Combining these gives a couple more equations:

    P = I<sup>2</sup>R = V<sup>2</sup>/R

    And you can rearrange them in various ways, e.g.:

    V = sqrt(PR).

    Does that help?
     
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  5. Saith Registered Senior Member

    Messages:
    149
    I see what's wrong now. The 4 problems came from the 4 equations that were * 2 instead of ^ 2. The program that I used to get the equations for mine showed it as * 2.
     
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