Why is the lightning rod on the roof, and the lightning doesn't break on the roof? Isn't it very?
In a thunderstorm, building over charged clouds, thunder and needle are at the top of the tall building on a large number of induction charge, due to lightning needle is pointed, and the electrostatic induction, the tip conductor always gathered the most charge. In this way, the lightning rod gathers most of the charge.
The lightning rod guides the lightning to discharge, and then the lightning current is introduced into the ground through the grounding lead and the grounding device, so as to protect the object from being struck by lightning.
The lightning rod also forms a capacitor with these charged clouds. Because of its sharp tip, the two plate of the capacitor is facing a small area, and the capacitance is very small, that is to say, it can hold very little charge. And it brings together most of the charge, so when there is more charge on the clouds, the air between the lightning rod and the cloud is easily broken down and become a conductor. Thus, the electrified cloud layer forms a passage with the lightning rod, and the lightning rod is grounded. The lightning rod can guide the earth's electric charges to the earth so that it does not pose a danger to the high-rise buildings and ensures its safety.
