Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Step up transformer

  1. Sep 26, 2008 #1
    Hi, so I know that VI = P cos (theta), but during an experiment using a step up transformer,

    I got the primary voltage 7.42V, primary current 0.41A, and primary power 3.2W. How then should I calculate the angle theta. I can't use arcosine, 'cause that will give me undefined.

    Thanks a lot.
     
  2. jcsd
  3. Sep 26, 2008 #2
    Doesn't sound right. You have Power in Watts (3.2) higher than the VA figure (3.042)

    And P = VI x Cos phi
     
  4. Sep 27, 2008 #3

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    How are you measuring the power? And the voltage and current, for that matter?

    As Pumblechook said, P should be less than or equal to V*I=3.04 VA
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Step up transformer
  1. Step Up Transformer (Replies: 2)

  2. Step Up Transformer (Replies: 5)

Loading...