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Name: A. B.
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: 2000-2001


Question:
Why does the lightning conductor have pointed shape? I know it has something to do with electric field lines. Please explain.


Replies:
The electric field in a conductor is very strong at a sharp edge or point so it provides a good target for a lightning discharge. You can find the quantitative details in a text on electricity and magnetism. Richard Fey also gives a good treatment in Vol. 2 Chapter 9 of "Lectures on Physics". In addition, check out the website: http://www.exploratorium.edu/ronh/weather/weather.html

It has a lot of good information.

Vince Calder


Electrons tend to move to and from pointed objects. They tend to remain on smooth round surfaces (like the globes on a Van de Graf generator). We do not want a charge to build up between buildings and clouds until a sudden discharge can do great damage. Instead, by applying a pointed lightning rod the charge is dissipated slowly keeping the electrical potential difference low. Unlike the Hollywood version, lightning seldom strikes a lightning rod.

Larry K.



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