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: Resistors and Voltage

  1. Apr 3, 2010 #1
    1. The problem statement, all variables and given/known data
    Provided that the output voltage is 4V, which one or more resistors can be removed to get the same output voltage.

    2. Relevant equations

    3. The attempt at a solution
    Im not sure if any working out is necessary here or not

    Attached Files:

  2. jcsd
  3. Apr 3, 2010 #2


    User Avatar
    Homework Helper

    From the given data, find the emf of the cell.
    To get the same output, what to do with X and Z so that the current in Y is 2 mA ?
  4. Apr 3, 2010 #3
    Think about it this way: If you combined X and Y in series, you'd have two parallel resistors. If you removed one of those parallel resistors(Z!), the voltage across and the current through the other parallel resistor does not change.
  5. Apr 4, 2010 #4
    okay EMF I calculated to be 6V, and then I combined X and Y to make another 3000ohm resistor and because I want output to be 4V, then that would mean current has to change from 2mA to 1.33mA correct? which means i can remove Resistor Z. Is that right im not sure
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook