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    1. The problem statement, all variables and given/known data
    hi
    i am wondering if this is correct. this is the question;
    Three cells, each of e.m.f. 1·5 V and internal resistance 0·50 ?, are connected in series to
    make a battery of e.m.f. 4·5V. The battery is connected to a resistor, R, of resistance 6·0 ?.



    2. Relevant equations
    V= i/R


    3. The attempt at a solution
    TOTAL VOLTAGE = 4.5V
    TOTAL RESISTANCE = 6.5 OHMS
    but the answer states the total resistnace is 7.5 ohms.
    can someone kindly explain how?
    thanks
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    (Original post by aurao2003)
    1. The problem statement, all variables and given/known data
    hi
    i am wondering if this is correct. this is the question;
    Three cells, each of e.m.f. 1·5 V and internal resistance 0·50 ?, are connected in series to
    make a battery of e.m.f. 4·5V. The battery is connected to a resistor, R, of resistance 6·0 ?.



    2. Relevant equations
    V= i/R


    3. The attempt at a solution
    TOTAL VOLTAGE = 4.5V
    TOTAL RESISTANCE = 6.5 OHMS
    but the answer states the total resistnace is 7.5 ohms.
    can someone kindly explain how?
    thanks
    When components are connected in series you simply add the resistance.

    Hence, 0.5+0.5+0.5+6 = 7.5 ohms
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    V = IR not I/R
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    (Original post by eswnl)
    V = IR not I/R
    thanks. silly me.
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    Yeah, I think you may have just misread:

    "each of ... internal resistance 0·50"

    So there's 3 lots of 0.5.
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    The compnents in this circuit with resistance are:

    3 batteries (each of 0.5 ohms)
    1 resistor (6 ohms)

    (3 x 0.5) + 6 = 7.5 ohms.

    Hope this helps!
 
 
 
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