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Homework Help: How Six 2V lamps could be lit to their normal brightness.

  1. Nov 17, 2015 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution

    I'm not really sure how to attempt this question tbh. In order for the lamps to have normal brightness I think the circuit must be parallel. I also think maybe for A there can only be one lamp per branch because there's only 2V available, for B there can be 3 per row and for C it can just be series?
  2. jcsd
  3. Nov 17, 2015 #2


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    Your attempt seems to be correct.
  4. Nov 17, 2015 #3
    Thank you :D I guess I did know haha. Any chance you could help with this?

    a) I know how to draw the circuit.
    b) I'm completely stuck on B. I'm guessing it involves omhs law but I can't see where.
    c) I can answer C with Potential difference (V) = current (I) x resistance (R).
    d) I'm not sure how to work out this.
  5. Nov 17, 2015 #4


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    What is the p.d. across X?
  6. Nov 17, 2015 #5
    Potential difference (V) = current (I) x resistance (R)

    Potential difference (V) = 2 x Resistor X?
  7. Nov 17, 2015 #6


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    Yes, we'd like to help you with this, but at first please start a new thread with this problem. According to the forum rules only one problem should be discussed in each thread.
  8. Nov 17, 2015 #7
  9. Nov 17, 2015 #8
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