1. Not finding help here? Sign up for a free 30min 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!

Electricity Calculation. I=Q/t

Tags:
  1. Jun 11, 2016 #1
    1. The problem statement, all variables and given/known data
    Ammeter shows 1.2 A and 1.0 A. How large amount of charge passing through the lamp in 1 minute?
    https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/84/84982-6e293679b3592fb475f0f9cac697526f.jpg [Broken]

    2. Relevant equations
    Q=I*t


    3. The attempt at a solution
    I = 1.2 + 1.0 = 2.2
    t = 1 * 60 = 60
    Q = I*t

    = 2.2 * 60 = 183 C
     

    Attached Files:

    • 1.png
      1.png
      File size:
      1.5 KB
      Views:
      71
    Last edited by a moderator: May 8, 2017
  2. jcsd
  3. Jun 11, 2016 #2

    cnh1995

    User Avatar
    Homework Helper

    Are you sure the current through the lamp is 2.2A?
     
  4. Jun 11, 2016 #3
    That's why I'm here for help.
     
  5. Jun 11, 2016 #4

    cnh1995

    User Avatar
    Homework Helper

    Why do you think the meters show different currents?
     
  6. Jun 11, 2016 #5
    Cuz they have different currents.
     
  7. Jun 11, 2016 #6

    cnh1995

    User Avatar
    Homework Helper

    One meter shows 1.2A and other shows 1A. Where does the remaining current go?
     
  8. Jun 11, 2016 #7
    I don't know. That's the question I got from my teacher. that's why I'm here for solutions.
     
  9. Jun 11, 2016 #8

    cnh1995

    User Avatar
    Homework Helper

    Well, providing direct answers is against the rules here. Helpers will only provide hints. Where do you think the current splits? Which meter will show 1.2A and which one will show 1A? Think on these and previous questions.
     
  10. Jun 11, 2016 #9
    I am here to find out if my equation is correct.
     
  11. Jun 11, 2016 #10
    I am sure you have been taught Kirchoff's Current Law and how to apply it in problems. What do you get if you apply this law at the middle point at the right side of the circuit?
     
  12. Jun 11, 2016 #11

    cnh1995

    User Avatar
    Homework Helper

    Q=I*t is always true.
    This is not correct.
     
  13. Jun 11, 2016 #12
    Thanks
     
  14. Jun 11, 2016 #13

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    On my tablet computer i can only view one of the images in the original post but.....Putting an ammeter in parallel with a lamp as shown in the second image isn't recommended.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted