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!

Magnitude and Direction of induced voltage

  1. May 3, 2016 #1
    1. The problem statement, all variables and given/known data
    Hey everyone I have a physics e&m question:

    http://blob:https%3A//www.physicsforums.com/aa779f37-be23-43d7-a888-d70263a3854b upload_2016-5-3_1-7-6.png

    2. Relevant equations


    3. The attempt at a solution

    upload_2016-5-3_1-7-31.png
    I took the derivative to find the magnitude of the induced voltage. (do I need to add a constant c?)
    I am having trouble with the direction of the current flow though... Do I use the right hand rule?

    Thanks!
     

    Attached Files:

  2. jcsd
  3. May 3, 2016 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    The constant "c" is usually either the speed of light in a vacuum or the constant of integration ... do either of these situation apply here?
    The current flow is determined by the right hand rule in conjunction with a law of physics that applies to induced currents.
    I'm puzzled you started at (c) ... did you do (a) and (b)?
     
  4. May 3, 2016 #3

    andrevdh

    User Avatar
    Homework Helper

    4 a) Does the question ask for the magnetic (flux) ?

    Oh, it should read the magnitude, not magnetic!

    Shouldn't you use Faraday's law?
     
  5. May 3, 2016 #4

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

  6. May 3, 2016 #5

    andrevdh

    User Avatar
    Homework Helper

    There might be a small gap in the lower right-hand part of the loop
     
  7. May 3, 2016 #6

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Well spotted - there may well be.
     
  8. May 3, 2016 #7
    Sorry! Yeah I meant magnitude.
     
    Last edited: May 3, 2016
  9. May 3, 2016 #8
    Okay so the derivative of magnetic flux is the induced voltage. I am having trouble calculating flux. Flux = BA cos (theta). How do I get the area....?
     
  10. May 3, 2016 #9

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    What shape is the area in question?
     
  11. May 3, 2016 #10
    Ahh I forgot that they gave us the length of the square. I think I was able to get it.
    13149837_10208152309959848_930633277_n_zpsdro9gsiq.jpg
    Does this look right?
     
  12. May 3, 2016 #11

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    in (c) and (d) the flux density is different in different parts of the square, how did you account for this?
    (hint: the variable y should not be in your answer)
    in (b) the question asks for the direction of the current
     
  13. May 3, 2016 #12
    For b) I say it is counterclockwise. My reasoning is that the field is decreasing as time passes (e^(-t)). The field will want to come out and the way to do that is for the induced current to flow counterclockwise.

    I am not clear on c). Doesn't the y variable account for the different flux values for different y values?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Magnitude and Direction of induced voltage
  1. Induced Voltage (Replies: 3)

Loading...