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Calculating power of one of two resistors

  1. Sep 23, 2014 #1
    1. The problem statement, all variables and given/known data
    Two resistors R1 and R2 are connected in series to a battery supplying a voltage of ∆V as shown. How much power is dissipated by the resistor R2 in the form of heat? Use the following data: R1 = 10 Ω, R2 = 5 Ω, ∆V = 3 V
    http://tinypic.com/r/153tr91/8

    2. Relevant equations

    Rtotal = R1 + R2
    P=V^2/R
    P= I^2 x R


    3. The attempt at a solution
    Rtot = 10 + 15 = 15 ohms
    I = 3/15 = .2 A
    P = (.2^2) x 10 = .4 W


    Why is this the wrong answer??
     
  2. jcsd
  3. Sep 23, 2014 #2
    Because R2 = 5 Ohms, not 10 Ohms
     
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