2021年08月03日

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30.07489098904JComponentHelper::renderComponent( ).../application.php:194
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60.07869436872JController->execute( ).../content.php:16
70.07869437256ContentController->display( ).../controller.php:761
80.08189987176JController->display( ).../controller.php:74
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20.07449081288JSite->dispatch( ).../index.php:42
30.07489098904JComponentHelper::renderComponent( ).../application.php:194
40.07669142632JComponentHelper::executeComponent( ).../helper.php:348
50.07669163432require_once( '/home/users/1/jein/web/jein/components/com_content/content.php' ).../helper.php:380
60.07869436872JController->execute( ).../content.php:16
70.07869437256ContentController->display( ).../controller.php:761
80.08189987176JController->display( ).../controller.php:74
90.085110559920ContentViewArticle->display( ).../controller.php:722
100.100311790992JDispatcher->trigger( ).../view.html.php:121
110.100411792800JEvent->update( ).../dispatcher.php:161
120.100411793728call_user_func_array:{/home/users/1/jein/web/jein/libraries/joomla/event/event.php:71} ( ).../event.php:71
130.100411793808plgContentJw_allvideos->onContentPrepare( ).../event.php:71
140.100411796456plgContentJw_allvideos->renderAllVideos( ).../jw_allvideos.php:41

釘を磁化する(EM-M-08)

<釘を磁化する/磁化の原理>

 

鉄などが磁石になるのは、鉄の中の原子の磁石(簡単のために「豆磁石」と呼びます)の向きがそろうことが必要です。
磁界の中に鉄を置くと、鉄の中の豆磁石の向きが揃って磁石になります。磁石を近づけるだけで鉄は磁石になりますが、磁石のN極あるいはS極を鉄に一方向に何度もこすりつけると、より豆磁石がそろうようになって鉄の磁力が強くなります。

鉄の中の豆磁石が、周りに近づけた磁石にどのように反応してそろっていくかを模型で説明しています。
磁石を近づけたりこすりつけたりする方法によって、磁石になった鉄の極がどうなるかをいろいろ考えてみましょう。