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!

Basic Generator problem

  1. Mar 10, 2004 #1
    The question is:
    A simple generator has a 655 loop square coil 19.7cm on a side. How fast must it turn in a .490 T field to produce a 110V peak output? give your answer in radians/second

    I used V=NBAwsin(wt)
    where V = 110, N=655, B=.490, A=.197*.197, w simplifies to 2*pi*f, wt simplifies to 2*pi
    so plugging in, 110=655*.490*.197*.197*2*3.14*f*sin(6.28)

    i get f = 12.85 rev/s * 360/57.3 = 80.76 rad/s

    but this is wrong..

    anyone know where i went wrong?
    places i suspect are: wrong formula, and i am using the sin(6.28) incorrectly..

    any hints?
  2. jcsd
  3. Mar 10, 2004 #2
    Well, sin(2*pi) is equal to zero using trig circles. There is one problem.
  4. Mar 10, 2004 #3
    Also the peak emf is E(o) not simply E so you can use the following equation:

    E(o)* sin(wt) = NAB w sin(wt)= E

    This simplifies to:

    E(o) = NAB*w

    Solve for w.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook