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!

Power and current

  1. Apr 10, 2007 #1
    1. The problem statement, all variables and given/known data
    An electric current described by I = 12 sin(250t) flows through a 20 ohm resistor. Calculate the power dissipated as heat.


    2. Relevant equations
    V=IR
    P=IV
    P = I^2*R


    3. The attempt at a solution
    Using the last equation, P = I^2*R
    P = 2880 sin^2(250t)
    Is that the best answer I can give? The question gives no information about efficency so I'm not sure if I'm forgetting an equation or something. It doesn't give a value for time either.
     
  2. jcsd
  3. Apr 10, 2007 #2
    I think you misinterpreted the problem. The problem asks for the power dissipated as heat, not the power in the element.
     
  4. Apr 11, 2007 #3

    Mentz114

    User Avatar
    Gold Member

    You need to integrate over a time period then divide by the period to get the root mean square (rms) value.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Power and current
  1. Current and Power (Replies: 7)

  2. Current & Power (Replies: 5)

Loading...