How to light bulb with potato

Science and Research reached almost everywhere and it is become essential part of life. Everyday new research going on around the world, but have you ever heard that you can light a bulb with potato?  Well it’s true 

How actually potato lights bulb?
The chemical reaction that takes place between two dissimilar metals and the juices in the potato create a small amount of voltage that can power a very small electrical device. Source:  Science How

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