Why did ray hit the lightning rod?
The lightning rod and the clouds and the formation of a charged capacitor, since it is pointed that the capacitor two is on the plate area is very small, the capacitance is also very small, that is to say it can hold less charge. But it also gathered most of the charge, so when the charge is on for a long time, it is easy between lightning rod and the clouds of air breakdown, become a conductor. In this way, the charged clouds and lightning formation pathways, and lightning and grounding lightning. You can put the charge on the earth by the clouds, the high-rise buildings not constitute a danger to ensure its safety.
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. So, the lightning rod gathered most of the charge.
In fact, the lightning rod should be called "lead lightning needle" is appropriate
