恒定电路中电流做功实质上是导体中的恒定电场对自由电荷的静电力做功,而导体中自由电荷在静电力作用下的运动是自由电荷在导体内的热运动和静电力作用下的运动的一种合运动,因此导体中自由电荷在静电力作用下的运动要远比真空中的电荷在静电 In a constant current circuit, the work done by the current is essentially a constant electric field in the conductor doing work on the free-charge electrostatic force. The movement of the free charge in the conductor under the action of the electrostatic force is the movement of the free charge in the conductor by thermal and electrostatic forces A kind of combined movement, so the free charge in the conductor under the action of electrostatic force than the charge in the vacuum in the static