第一篇:物理八下期末复习总结
本章从电压入手,引导学生利用电压表来探究串联,并联电路中的电压规律,运用“控制变量法”研究电阻与其影响因素之间的关系,初步了解半导体,超导体的一些特点,会正确把滑动变阻器连入电路中并用其来改变电路中的电流和电压,本章内容是学习电学知识,掌握欧姆定律的基础。
电压和电阻
电压
作用:电压是使电路形成电流的原因
常用单位以及换算:千伏,毫伏,微伏1kv=1000v1v=1000mv1mv=1000uv
电压的测量——电压表
1读数:看清量程,弄清每大格和每小格表示电压数
2接法:并联在被测电路两端,使标有﹣号的接线柱接电源的负极,标有﹢号的接线柱接电源的正极,被测电压不超过电压表的量程
串联,并联电路电压的规律
串联电路中总电压等于各部分电路
中分电压之和
并联电路中各支路两端电压都相等
电阻
电阻的意义:一切导体都具有阻碍电流作用的性质,不同的导体对电流阻碍作用不同
单位:欧姆ω,其他常用的单位:兆欧mω、千欧kω1mω=1000klω=1000000ω
影响电阻大小的因素:长度、材料、横 ……此处隐藏6449个字……ove to go but i can't.my parents are out on business.they are coming back next month.and now i have to look after my grandma because she is ill in bed.and i also need to study for my coming end-of-year exam.i'm very sorry but i can't go to your party.thank you for asking me.i hope you can have a good time.
话题十五:暑假及期末复习星沙英语li ping the summer holidays are coming soon.several days ago ,i was very tired because iwas busy doing a lot of exercises.now i`m having exams.some of my classmats are nervous about the exams,but i`m very happy in a few days,i am going to have a good rest during the holidays. i will go sightseeing. at the same time ,i am also going to visit my friends and relatives. i am sure i will spend my holidays happily.