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

Help me with this circuit

  1. Apr 10, 2014 #1
    if i just measure the resistance btw L and N , the resistance should be zero right, then how can it be 0.3 ohms ?

    Attached Files:

  2. jcsd
  3. Apr 10, 2014 #2


    User Avatar

    Staff: Mentor

    What information are you given about the source impedance for the AC Mains feed of Line and Neutral into this circuit? The source impedance is in parallel with the circuit impedance.

    Is this for schoolwork? If so, I will move your posts to the Homework Help forums.
  4. Apr 10, 2014 #3
    im using the software for Troubleshooting Electrical circuits by BNN. studying this to get prepared as electrician. for if you look at the last 2 pictures, you can see that you can still get 0.3 ohms if the black wire is unplugged
    Last edited by a moderator: Apr 10, 2014
  5. Apr 11, 2014 #4
    I guess by zero resistance you mean infinite resistance. And does the circuit work as it should (all switches on - bulb shines, at least one off - bulb off). I hope, you measure it when you have the circuit disconnected from power source. And by the way, you measure on real circuit or are we still talking about that SW?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook