Hi, dear forum members! It is well known, that if one makes the current carrying wire more thicker, for example 3 times, that means the current goes up also 3 times. Microscopically that seems plausible, because, when we consider that a cross section is made of atoms, then it is apparent, that making the cross sectional area larger 3 times, means that one makes the number of atoms building up the cross-section also 3 times bigger. If we consider that every atom has one loose electron, then it is very plausible that the number of electrons accelerating through the cross section per unit time is also 3 times larger. That is equal to saying that the current is 3 times larger. It also well known that the power that the piece of wire exhibits, is P= Iˇ2 * R. Mathematically, it all makes sense, until one starts to think about it conceptually. According to one model, electrons accelerate due to the electric field and collide with the atomic cores. Well, suppose that the field is uniform and that every electron accelerates the same way (for simplicity). That means that each electron collides, having a certain amount of energy (mvˇ2)/2. 3 times larger cross-section means 3 times more atoms per cross- section, which means 3 times more electrons colliding. Since each electron is giving away a certain amount of energy (mvˇ2)/2, that means that the 3 times more electrons should give away 3 times more energy during the same time unit. Multiplying it by the length of the wire, we can get the entire amount of energy that the wire exhibits during this time unit. It is STILL 3 times larger, NOT 9 times as the equation predicts. What is wrong with the reasoning? I have a few ideas myself, but I would very much like to see your opinions on this matter. Kind regards!