1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

A transformer problem

  1. Oct 13, 2005 #1

    My Question:

    A model train transformer plugs into 120-V ac and draws 0.35A while supplying 7.5A to the train. (a)What voltage is present across the tracks? (b) is the transformer step-up or step down?


    Part A:


    Part B:

    Step-down, because the secondary voltage is lower than the primary voltage.

    Is it correct:confused:

    Thank You:smile:
  2. jcsd
  3. Oct 14, 2005 #2

    Doc Al

    User Avatar

    Staff: Mentor

    You are correct. (Note typo in your part A equations: you wrote "0.25A" instead of "0.35A".)
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook