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!

Alternating Current. (When can we see it?)

  1. May 24, 2009 #1
    Hello there my fellow chemical structures!

    I was just wondering the other day, while staring vacantly at a lighting fixture: How slow would the AC going back and forth through the light bulb have to be before you could see it flickering?

    Any information would be much obliged.

    Thanks in advance.
  2. jcsd
  3. May 24, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You might want to investigate http://en.wikipedia.org/wiki/Persistence_of_vision" [Broken]. A couple fine points with incandescent lighting: first, the filament will flicker twice for each AC cycle, since resistive heating is independent of current direction. Second, the filament won't go dark instantaneously but will cool down over a time period that depends on the thickness, material, and geometry of the filament. Empirically, I'd expect the minimum frequency to be on the order of 10 Hz, but I don't have a frequency generator handy; perhaps someone else does.
    Last edited by a moderator: May 4, 2017
  4. May 25, 2009 #3
  5. May 25, 2009 #4
    Incandescent bublbs don't easily show flicker because of the temperature of the filament. A flourescent bulb can be seen at 60 Hz.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Alternating Current. (When can we see it?)
  1. Can we see electrons? (Replies: 1)