欧姆定律[Ohm's Law] - 达人(其实～我是卧底，来自外星)

2005/05/09 | 欧姆定律[Ohm's Law]
类别(Ω〖物理〗) | 评论(0) | 阅读(85) | 发表于 12:49: The current I is related to the surface integral of the current density J by
(1)

(2)

where use has been made of the relation
(3)

with the conductivity and E the electric field.If is constant, then
(4)

Now, for a wire, E and are constant and perpendicular, so
(5)

where A is the cross sectional area, V is the voltage, and L is the length of the wire. Plugging in gives
(6)

Defining the resistance
(7)

and solving for V gives Ohm's law,
(8); 0