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Resistors in Parallel!

  1. Feb 26, 2007 #1
    1. Ten 110-ohm lamps are connected in parallel to a 110-V house line. A) What is the combined resistance of the ten lamps? B) What current flows in the line when all ten lamps are operating? C) What power is then being supplied to the circuit by the line?

    I just wanted to have someone check my work and see if I attacked this problem the right way.

    2. 1 / Rt = 1 / r1 + 1 / r2...... (total resistance for resistors in parallel)
    V = IR
    P = VI

    3. A) This is simple: add (1/110) ten times, giving (1/11).. Then cross multiplication can be used to find that Total resistance is equal to 11 ohms

    B) To find the current that flows in the line, we can use ohms law and substitute 110 volts = 11 ohms * I, and I will evaluate to 10 amps

    C) P = (110 volts)(10 amps) = 1100 right?
  2. jcsd
  3. Feb 26, 2007 #2
    Looks good to me.

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