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    https://isaacphysics.org/questions/i...ance_in_series

    Somebody, please enlighten me...

    I know that E=IR+Ir
    my current working out looks something like this:

    Current for 1 cell = V1/(20+r)
    Current for 2 cells = 1.5V1/(20+2r)

    E=(V1/(20+r))*20 + (V1/(20+r))*r

    2E=(1.5V1/(20+2r))*20 + (1.5V1/(20+2r))*2r
    I'm not sure if you multiply by r or 2r

    (V1/(20+r))*20 + (V1/(20+r))*r = (1.5V1/(20+2r))*20 + (1.5V1/(20+2r))*2r
    This is where I get stuck...
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    (Original post by Mowahid)
    https://isaacphysics.org/questions/i...ance_in_series

    Somebody, please enlighten me, my head hurts too much after trying to solve this for the past hour.

    I know that E=IR+Ir
    my current working out looks something like this:

    Current for 1 cell = V1/(20+r)
    Current for 2 cells = 1.5V1/(20+2r)

    E=(V1/(20+r))*20 + (V1/(20+r))*r

    2E=(1.5V1/(20+2r))*20 + (1.5V1/(20+2r))*2r
    I'm not sure if you multiply by r or 2r

    (V1/(20+r))*20 + (V1/(20+r))*r = (1.5V1/(20+2r))*20 + (1.5V1/(20+2r))*2r
    This is where I get stuck...

    For one cell case, the p.d. across the external resistor R is V1, so you can use it to find the current through the cell.

     I_1 = \dfrac{V_1}{R}

    You can do the same to find the current through the two cells for the two cells case.

    For the two cells case,


    2E = I2 (R + 2r)
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    (Original post by Mowahid)
    https://isaacphysics.org/questions/i...ance_in_series

    Somebody, please enlighten me, my head hurts too much after trying to solve this for the past hour.

    I know that E=IR+Ir
    my current working out looks something like this:

    Current for 1 cell = V1/(20+r)
    Current for 2 cells = 1.5V1/(20+2r)

    E=(V1/(20+r))*20 + (V1/(20+r))*r

    2E=(1.5V1/(20+2r))*20 + (1.5V1/(20+2r))*2r
    I'm not sure if you multiply by r or 2r

    (V1/(20+r))*20 + (V1/(20+r))*r = (1.5V1/(20+2r))*20 + (1.5V1/(20+2r))*2r
    This is where I get stuck...
    Did you quote my reply? But I cannot see your reply.
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    Just wanted to say thanks for the help, didn't really know how
 
 
 
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