1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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 between two points

  1. Dec 10, 2012 #1
    A battery has a voltage of 107.5 V. We denote this battery with point B. Point C is the point after two resistors, which are parallel to one another. Immediately after point C we get one more resistor. Calculate the voltage between B and C.

    I calculated the total resistance between B and C and from there, I calculated the voltage. However my teacher says that I should take resistor 3, which is situated after point C. Is it just me, or is he wrong?
  2. jcsd
  3. Dec 10, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    It's hard to interpret what your circuit looks like from the description but it looks like

    Battery +ve --- Point B --- 2 resistors in parallel --- Point C ---- one resistor --- Battery -ve

    If that is correct..

    Step 1 Convert the two resistors in parallel to one..

    Battery +ve --- Point B --- one resistor(R1) --- Point C ---- one resistor(R2) --- Battery -ve

    Then the voltage at point C with respect to the battery -ve can be calculated using the potential divider rule..

    Vc = Vbat * R2/(R1+R2)

    The voltage requested Vb-Vc = Vbat - Vc = Vb - (Vbat * R2/(R1+R2))
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Voltage between points Date
Calculate the voltage between points A and B Mar 27, 2017
Voltage drop between two points Dec 3, 2015
Voltage between two points Nov 27, 2015
Voltage between two points of a circuit Nov 15, 2015