1. Not finding help here? Sign up for a free 30min 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!

Voltage and Resistance Exercise, please help.

  1. May 12, 2007 #1
    Please help with the following exercise:

    Given 2 resistors in series R1=10 ohms, R2= 30 ohms, determine the current flowing through the resistors and the voltage across each resistor, if the potential difference across the wire is V=12V.

    This is how I solved it:

    The total resistance Req= R1+R2= 40 ohms

    R = V / i
    i = V/R = 0.3 A

    V(R1) = -R1*i = -10*0.3= -3V
    V(R2) = -R2*i = -30*0.3= -9V

    Is it correct? Can the voltage be negative? Please help.

    Thank you.
     
  2. jcsd
  3. May 12, 2007 #2
    Voltage can be negative because it is a relative measurement.

    I don't think you did yours right though. Draw the circuit out, and sum the voltages. They should sum to zero because of energy conservation, or otherwise known as Kirchoff's Voltage Law.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Voltage and Resistance Exercise, please help.
Loading...