随着家用电器的日益增多,人们往往选用导电性能好的粗铜芯线来代替导电性能较差的细铝芯线,但在制作滑动变阻器时却又选用导电性能较差的镍铬合金丝,这些看起来矛盾的现象,都与导体的电阻有关.电阻是电学的一个重要物理量,它是初中电学学习的核心内容之一.那么,什么是电阻?它的大小由什么决定?怎样测量它的大小?下面我们就一起来认识电阻. With the increasing number of household appliances, people tend to use a good conductive copper foil instead of the poor conductivity of the fine aluminum core wire, but in the production of sliding rheostat but the poor conductivity of nickel-chromium alloy wire, These seemingly contradictory phenomena are all related to the resistance of the conductor, which is an important physical quantity of electricity and one of the core elements of junior high school electrical learning. So what is resistance? What is its size and how is it measured? Size? Here we come together to understand the resistance.