انهن لا جيڪي ٿيوري سمجهڻ چاهين ٿا۔
The lemon juice is an acid which acts as a catalyst to enhance the reaction, to it we add sodium chloride (table salt) to reduce the internal resistance of the battery. We will cut thin cardboard pieces to the size of a penny, soak them in the acidic electrolyte, and sandwich them between nickels and pennies. It just so happens that the 3 AA battery packs common in cheap LED flashlights are just a tiny bit smaller than a US nickel, which is why I chose this arrangement.
انهن لاِ جيڪي ڪيميسٽري جي انفارميشن وٺڻ چاهين ٿا۔
For those who want more chemistry information:
A galvanic voltaic cell contains two metals which are dissimilar in electrical potential, separated by a thin barrier. To this cell we then add an electrolyte which causes the electrochemical reaction to occur. The metal contains cations, ions heavy with protons; cations react with water containing anions (electron heavy). While one metal causes the reduction of oxidation in the other, the reaction of anions and cations create an exchange of electrons - an electric current.