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Question regarding voltage, current and resistance

  1. Aug 26, 2014 #1
    It's impossible for an object to have no resistance but I was wondering if theoretically such a thing was possible, shouldn't the current flow infinitely fast? But instead, no current exists at all (V=I*0=0). And if the current remains the same, how come the voltage increases as I increase resistance? I'm sorry for the stupid questions.
     
  2. jcsd
  3. Aug 26, 2014 #2
    Current is always limited to the speed of light.

    In your equation (V=IR), V = 0 when R = 0, but I can be any number. Certain materials, called superconductors, have zero resistance as long as they remain sufficiently cooled. Think of voltage as work, and resistance as friction. If you push a box across the cement, you have to continuously push and do work on it because of the friction. The more friction there is, the more work you have to do to maintain the same speed. A box on a frictionless surface will continue to move at the same speed it started at without any work at all (assuming no air resistance). This is similar to the zero resistance, zero voltage scenario.
     
    Last edited: Aug 26, 2014
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