ohs law

Discussion in 'Physics' started by reviratilla, Feb 16, 2004.

  1. reviratilla

    Thread Starter New Member

    Feb 16, 2004
    explain the interrelationship of the voltage, current and resistance
  2. Dave

    Retired Moderator

    Nov 17, 2003
    The voltage across a component is proprotional to the current through it, where the resistance is the constant of proportionality, i.e:

    Voltage = Resistance x Current

    V = I x R

    By rearranging the formula:

    I = V / R


    R = V / I
  3. Tada

    New Member

    Jan 26, 2004
    Ah lets give an analogy.

    Current is how much is flowing through, which is actually the +, but for working out problems the electrons -. Current is the rate of change of charges

    Now lets say each electron is like a drop of water. So 23 Amps is like 23 electrons flowing through that specific area per second

    Voltage is potential, or how much potential energy it has, that will allow it to go to the reference point.

    So say we have a rock in the middle of the river representing the resistance, its not going to change the potential energy, but it will change the rate of change of charges. So using those relationships in the comment above you can figure ohms crap out.
  4. Nirvana

    Well-Known Member

    Jan 18, 2005
    Hi there, just to make it clear 23 electrons flowing does NOT mean that 23 amps are flowing. In fact one Amp would flow if one Coulomb of charge flowed passed a reference point in one second. Now a single electron has a charge approximately equal to 1.6 x10^-19 Coulombs. Therefore you can see that it would take 1.6x10 ^ 20 electrons to form one Coulomb and hence an amp - a lot more than 23.
  5. Salgat

    Active Member

    Dec 23, 2006
    Think of it this way. You typically have a constant Voltage. The total amount of resistance in the circuit(how much resistance to electricity) determines how much current(electrons) will flow through the circuit. An analogy is that in water pipe, the more resistance you have to the water(R), the less water will flow through(C), even with the same pressure(V).