1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Did I do this question correctly? (Loop Rule Q)

  1. Mar 30, 2014 #1
    A 9.0 V battery has an internal resistance of 0.50 ? and is connected to 5 resistors, as shown in the figure below. A) What is the equivalent resistance of all the resistors (not including the internal resistance of the battery)? B) What is the total current in the circuit? C) What is the voltage across the 10.0 ? resistor?

    What I've did:
    (1/req) = 1/R1 + 1/R2 + 1/R3
    (1/8) + (1/4) = 3/8 (or 2.7)
    2.7 + 6.0 = 8.7
    (1/8.7) + (1/10) = 187/870 (or 4.7)
    4.7 + 5.0 + 0.5 = 10.2
    I = V / R I = 9.0 / 10.2 = .88 A
    A.) 10.2 ?
    B.) .88 A

    C.) Voltage Across 5 = .88 x 5 = 4.4 V
    So, voltage across 10 = 9-4.4 = 4.6 V

    PLEASE TELL ME IF ALL OF THIS RIGHT. I need to get this problem correct. The circuit is attached.
     

    Attached Files:

  2. jcsd
  3. Mar 31, 2014 #2

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    It is hard to follow your calculations without any explanations. What does the first line do there?

    8/3 is not 2.7, you should not round to just one decimal digit here.
    At (A), check the problem statement: "not including the internal resistance of the battery".
    At (C), don't forget the voltage at the internal resistance.

    Apart from that, it looks fine.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Loading...