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【实验指导】新版教科版小学科学四年级下册2.8模拟安装照明电路
实验：模拟安装照明电路
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实验材料：电池、两个小灯泡和小灯座、两个开关、导线若干
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实验方法：
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1、画出小组设计的电路图，说出电池（房间电源）、两个小灯泡（两盏电灯）、两个开关各在什么位置？怎样组成一个电路？
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2、按照电路图组装电路。
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3、
检测电路。检查电流能否顺利通过小灯泡，开关能否控制小灯泡的亮与灭，
是
否有使电源短路的错误连接。
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理解与应用
电路连接的方法有串联和并联两种。我们家里的家用电器一般都是并联的。一节电池的电压是1.5V，两节电池串联起来的电压就是3V。所以把电池串联起来小灯泡会更亮些。两节电池并联起来，电压还是1.5V，所以小灯泡不会太亮。
电路中的电压超过了小灯泡上标的1.5V，灯泡太亮会烧坏灯泡的。电池串联，电压为3V，小灯泡亮，电池并联，电压仍然是1.5V，小灯泡暗。
精炼反馈
1.在一个电路中，串联两个灯泡比并联两个灯泡时(?
?
?
?
?)。
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A.亮
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B.暗
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C.一样亮
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【答案】B
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【详解】在同一个电路中，电路的总电压不会变，将小灯泡串联是将两个小灯泡的电压相加等于电路的电压；而并联则是每个小灯泡的电压都是总电路的电压，显然，将小灯泡并联的时候更亮，串联的时候更暗，所以本题的答案是B。
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2.在下面的电路中，小灯泡较亮的是(?
?
?
?
?
)。
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【答案】B
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【详解】如果将两个小灯泡串联，电路的总电压就是这两个小灯泡的和，如果将它们并联，那么电路的电压还是一个小灯泡的电压。显然三个选项中，B选项的电压最大。电压越大，灯泡越亮，故答案为B。
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