How do you make a light bulb light up with a lemon?

Question

I have read how it makes it light up but i wanna know what is the process or the steps? Im doing a science fair and want to know how to do this..

Answer 1

A simple DC cell can be created by putting metal probes in an acidic bath and creating a closed circuit.

Two different metals are used, each pokes into the lemon and connect out to a wire that goes to one of the light bulbs two terminals.