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!

Non ohmic device

  1. Feb 25, 2009 #1
    For a lab yesterday we recorded points to plot the I-V graphs for a few resistors and a light bulb. The light bulb was supposed to show that some that some devices don't obey ohms law but when plotting the graph im cutting more of a straight line then a curve showing that it DOES! Could this be because are voltage and current results came from a low power source that only dimly lit the bulb not giving it a chance to heat up? Or is this an error? How do i report this result>
  2. jcsd
  3. Feb 25, 2009 #2


    User Avatar
    Homework Helper

    Well for low current the filament won't heat much, so you won't read much difference. But if it is glowing at least it is pretty hot. If you put a resistor in series with the bulb you can measure the voltage across that with the bulb and without the bulb. Then you could measure the bulb alone with very low current of the voltmeter and demonstrate that its heated R is greater than its cold R.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Non ohmic device
  1. Ohmic Or NoN ohmic (Replies: 3)

  2. Ohmic resistor (Replies: 2)