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

Electricity question

  1. Nov 6, 2004 #1
    Just a simple question, if u have an electric circuit that has a DC power supply, and you set it to 8 volts, u have an ammeter, lightbulb and variable resistor also in the circuit, does the current in the circuit change as the resistance changes, or is the current always constant?
  2. jcsd
  3. Nov 6, 2004 #2
    i am not sure but due to the fact that you have a variable resistor and the ammeter is ideal, the current isn't constant. i think it is related to Ohm's law:
  4. Nov 6, 2004 #3

    Doc Al

    User Avatar

    Staff: Mentor

    For a series circuit, the relationship between voltage (V) and current (I) is given by V = IR, where R is the total resistance. So if you change the resistance, the current will change accordingly.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook