2022年中考物理同步系列:专题19生活用电复习学案 .pdf
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1、第十九章生活用电一、考点知识梳理(一)家庭电路1.家庭电路的组成:电能表、闸刀开关、保险丝。2.家庭电路的连接:各种用电器是并联接入电路的,插座与灯座是并联的,控制各用电器工作的开关与电器是串联的。3.家庭电路的各部分的作用:低压供电线:给用户提供家庭电压的线路,分为火线和零线。火线和零线之间有220V 的电压,火线和地线之间也有220V的电压,正常情况下,零线和地线之间电压为 0V 测电笔:用途:用来辨别火线和零线。种类:钢笔式,螺丝刀式。使用方法:手接触笔尾金属体,笔尖金属体接触火线,观察氖管是否发光。电能表:用途:测量用户消耗的电能(电功)的仪表。安装:安装在家庭电路的干路上,原因:这样
2、才能测出全部家用电器消耗的电能。铭牌:所标的电压U是:额定电压,所标的电流I 是:允许通过的最大电流,UI 是:电能表后能接用电器的最大功率,如果同时使用的家用电器的总瓦数超过这个数值,电能表的计数会不准确甚至烧坏。闸刀(空气开关):作用:控制整个电路的通断,以便检测电路更换设备。安装:家庭电路的干路上,空气开关的静触点接电源线 保险盒:材料:保险丝是由电阻率大、熔点较低的铅锑合金制成。保险原理:当过大的电流通过时,保险丝产生较多的热量使它的温度达到熔点,于是保险丝熔断,自动切断电路,起到保险作用电路符号:连接:与所保护的电路串联,且一般只接在火线上选择:保险丝的额定电流等于或稍大于家庭电路的
3、最大工作电流。规格:越粗额定电流越大。注意:不能用较粗的保险丝或铁丝、铜丝、铝丝等代替。因为铜丝的电阻小,产生的热量少,铜的熔点高,不易熔断。应用举例:某家庭需要使用10A 保险丝,可只有 5A 和 15A 保险丝。如何分别来代替使用:可用两根5A 保险丝并起来代用;可将15A保险丝用刀轻切一小口使剩余部分截面积和10A保险丝截面积相同。插座:作用:连接家用电器,给可移动家用电器供电。种类:固定插座、可移动插座、二孔插座、三孔插座安装:并联在家庭电路中,具体接线情况:1 接火线;2 接零线;3 接地线;4 接用电器的金属外壳;5 接用电部分的线路。把三脚插头插在三孔插座里,在把用电部分连入电路
4、的同时,也把用电器的金属外壳与大地连接起来,防止了外壳带电引起的触电事故。用电器(电灯)、开关:白炽灯是利用电流的热效应进行工作的,小功率的灯泡灯丝细而长,里面抽成真空。大功率的灯泡灯丝粗而短,里面抽成真空后,还要充入氮气、氩气等惰性气体,且气压为 0.1Pa,目的是平衡大气压对玻璃壳的压力。灯泡长期使用会变暗,原因是:灯丝升华变细电阻变小,实际功率变小;升华后的金属钨凝华在玻璃内壁上降低了灯泡的透明度。灯泡的种类:螺丝口、卡口。螺丝口灯泡的螺旋接灯头的螺旋套,进而接零线;灯泡尾部的金属柱接灯头的弹簧片,再通过开关接火线:原因:防止维修触电。开关和用电器串联,控制用电器,如果开关短路用电器会一
5、直工作开关不能控制,但不会烧干路上的保险丝。(二)家庭电路中电流过大的原因1.原因:发生短路、用电器总功率过大。文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3
6、R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U
7、5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9
8、B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4
9、C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H
10、3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6
11、T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R92.家庭电路保险丝烧断的原因:发生短路、用电器功率过大、选择了额定电流过小的保险丝。(三)安全用电1.对人体的安全电压是不高于36V,根据欧姆定律,电压
12、越高,通过人体的电流就会越大,对人就越危险。2.触电事故:定义:一定强度的电流通过人体所引起的伤害危险性:与电流的大小、通电时间的长短等因素有关。安全电压:不高于36V,动力电路电压380V,家庭电路电压220V都超出了安全电压。3.家庭电路低压触电的两种形式:单线触电和双线触电。家庭电路触电的事故:都是由于人体直接或间接跟火线接触造成的并与地线或零线构成通路。要分清零线和地线,虽然地线和零线正常情况下之间没有电压,但绝不能将地线和零线接通,否则易造成触电事故。3.高压触电的两种形式:高压电弧触电和跨步电压触电。4.安全用电原则:不接触低压带电体,不靠近高压带电体,不弄湿用电器,不损坏绝缘层。
13、5.触电事故的急救:如果发生了触电事故,要切断电源,必要时应该对触电者进行人工呼吸,同时尽快通知医务人员抢救。6.高大建筑物上的针状的防雷装置,叫做避雷针,高压输电铁塔最上面的两条导线是用来防雷的,我国古代建筑物上的龙角形铁制装饰物也有防雷作用。二、重点难点解读经典例题分析例 1:(2014?宁夏)关于家庭电路与安全用电,下列说法正确的是()A家庭电路短路时会烧坏用电器B当两孔插座的两个线头相碰时,会造成短路C家庭电路中空气开关跳闸,一定是接入了大功率用电器D使用试电笔时,手若接触笔尾金属体就会发生触电事故文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编
14、码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5
15、 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7
16、ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文
17、档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1
18、F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N
19、7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R
20、9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9考点:人教新课标物理九年级一轮复习?生活用电?家庭电路例 2:某同学家室内的电灯均正常工作,当他把“220V 8W”的台灯插头插入插座后,闭合台灯开关,室内电灯全部熄灭,发生这一现象的原因可能是()A插座处短路 B台灯插头处短路 C 台灯开关处短路D台灯灯头处短路例 3:(2013?黄冈)下列做法不符合安全用电要求的是()A用铜丝代替保险丝 B使用冰
21、箱时,电源插头插在三孔插座上C发生触电事故时,立即切断电源 D使用试电笔时,手指不能碰到笔尖文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3
22、H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N
23、6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L1
24、0K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:C
25、D3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ2N6T9B5N7 ZK9L10K4C3R9文档编码:CD3H3U5D1F5 HJ
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