字幕列表 影片播放 列印英文字幕 Smart Learning for All Topic: Earthing. Why do buildings have lightning rods? I know. They are used to dry clothes. No. They are used for earthing. Earthing means digging the earth, right? No. Earthing is the process of transferring charge from a charged object to the earth. It is done with the help of this lightning rod. A lightning rod is a metal rod whose lower end is fixed to a copper plate. Buried deep in the earth while upper end has spikes. But why is it called a lightning rod? This is because it protects us from lightning. Lightning is a flow of massive charge. It can damage an entire building and harm the people living in it. Hence, to protect them. The lightning rod transfers the massive charge from the lightning to the earth safely. For more educational videos please visit http://www.SmartLearningforAll.com Also, don't forget to subscribe to our YouTube channel.