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!

Homework Help: Ohmic resistor

  1. Aug 7, 2009 #1
    Can someone explain how I can find the resistance of an ohmic resistor of unknown resistance by setting up a simple circuit using a voltmeter and household appliances? Thanks
  2. jcsd
  3. Aug 7, 2009 #2


    User Avatar

    Staff: Mentor

    Thread moved to Intro Physics.

    What are your thoughts on how to approach this question? The simplest answer is that most voltmeters have resistance measuring capability, but I'm pretty sure that's not the answer that folks want you to come up with. If the meter can only measure voltage, and you only have one unknown value resistor (and no reference resistor), then what else can you do? What does the question mean by "household appliances"? Can you take them apart and take out batteries, cut out resistors that you can read the color code on to figure out their resistance and use them as references? What?
  4. Aug 7, 2009 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    I hope whoever posed the question is not thinking of using the resistance of a light bulb calculated from it's voltage and power ratings. That resistance calculation would actually be wrong at room temperature.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook