电阻的基本单位是欧姆，用希腊字母“Ω”表示，有这样的定义：导体上加上一伏特电压时，产生一安培电流所对应的阻值。-The basic unit of resistance is the ohm, the Greek letter "Ω", such a definition: plus one volt, the conductor produce a current of one ampere corresponding resistance.