資源簡介

【實驗指導】新版教科版小學科學四年級下冊2.8模擬安裝照明電路
實驗：模擬安裝照明電路
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489862&idx=2&sn=3bf254763f8919f84a8250187e5d7f1f&chksm=ebe3bf34dc9436225e6b798afa71eaade28623958896173fc4c15a86fa07fc77792bd84de053&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
實驗材料：電池、兩個小燈泡和小燈座、兩個開關、導線若干
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489862&idx=2&sn=3bf254763f8919f84a8250187e5d7f1f&chksm=ebe3bf34dc9436225e6b798afa71eaade28623958896173fc4c15a86fa07fc77792bd84de053&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
實驗方法：
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489862&idx=2&sn=3bf254763f8919f84a8250187e5d7f1f&chksm=ebe3bf34dc9436225e6b798afa71eaade28623958896173fc4c15a86fa07fc77792bd84de053&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
1、畫出小組設計的電路圖，說出電池（房間電源）、兩個小燈泡（兩盞電燈）、兩個開關各在什么位置？怎樣組成一個電路？
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489862&idx=2&sn=3bf254763f8919f84a8250187e5d7f1f&chksm=ebe3bf34dc9436225e6b798afa71eaade28623958896173fc4c15a86fa07fc77792bd84de053&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
2、按照電路圖組裝電路。
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489862&idx=2&sn=3bf254763f8919f84a8250187e5d7f1f&chksm=ebe3bf34dc9436225e6b798afa71eaade28623958896173fc4c15a86fa07fc77792bd84de053&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
3、
檢測電路。檢查電流能否順利通過小燈泡，開關能否控制小燈泡的亮與滅，
是
否有使電源短路的錯誤連接。
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489862&idx=2&sn=3bf254763f8919f84a8250187e5d7f1f&chksm=ebe3bf34dc9436225e6b798afa71eaade28623958896173fc4c15a86fa07fc77792bd84de053&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
理解與應用
電路連接的方法有串聯和并聯兩種。我們家里的家用電器一般都是并聯的。一節電池的電壓是1.5V，兩節電池串聯起來的電壓就是3V。所以把電池串聯起來小燈泡會更亮些。兩節電池并聯起來，電壓還是1.5V，所以小燈泡不會太亮。
電路中的電壓超過了小燈泡上標的1.5V，燈泡太亮會燒壞燈泡的。電池串聯，電壓為3V，小燈泡亮，電池并聯，電壓仍然是1.5V，小燈泡暗。
精煉反饋
1.在一個電路中，串聯兩個燈泡比并聯兩個燈泡時(?
?
?
?
?)。
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
A.亮
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
B.暗
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
C.一樣亮
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
【答案】B
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
【詳解】在同一個電路中，電路的總電壓不會變，將小燈泡串聯是將兩個小燈泡的電壓相加等于電路的電壓；而并聯則是每個小燈泡的電壓都是總電路的電壓，顯然，將小燈泡并聯的時候更亮，串聯的時候更暗，所以本題的答案是B。
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
2.在下面的電路中，小燈泡較亮的是(?
?
?
?
?
)。
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
【答案】B
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)
【詳解】如果將兩個小燈泡串聯，電路的總電壓就是這兩個小燈泡的和，如果將它們并聯，那么電路的電壓還是一個小燈泡的電壓。顯然三個選項中，B選項的電壓最大。電壓越大，燈泡越亮，故答案為B。
(?http:?/??/?mp.weixin.?/?s?__biz=MzI4NjA0NDk1Nw==&mid=2247489031&idx=1&sn=5fab1bb7a32246385cd16171b0ef5073&chksm=ebe3b075dc94396395a58721cf9f64e01251a7b12c3440c7753f5707ab4fc4621cc2569f09aa&scene=21"
\l
"wechat_redirect"
\t
"https:?/??/?mp.weixin.?/?_blank?)

展開更多......

收起↑