Lightning arrestors
When clouds move in the atmosphere, they rub against the air particles and produce a large amount of static charges by friction.
These charges induce large amounts of the opposite charge on the earth.
Hence a high potential difference is created between the earth and cloud.
This makes air to be a charge conductor.
The opposite charges attract each other and neutralize, causing thunder and lightning. Lightning can be very destructive to buildings and other structures.
Lightning arrestors are used to safeguard such structures.
It consists of a thick copper plate buried deep under the ground.
The plate is connected by a thick copper wire to the spikes at the top of the building.
The arrestor assumes the same charge as the earth. At the spikes, a high charge density builds up and a strong electric field develops between the cloud and the spikes. The air around the spikes is ionized. The opposite charges attract each other and neutralize.
Excess electrons flow to the ground through the thick copper wire.
It is for this reason that people are advised not to take shelter under trees when it is raining.
Moraa orina answered the question on April 10, 2018 at 05:17
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