Can anyone tell me how the Voltaic cell works? In my text book(grade 10 India), a diagram with a beaker containing Dilute Surlphuric acid , 1 zinc plate(with negative signs all over it), 1 copper plate(positive signs all over it) and the 2 plates are connectedto a bulb. I want to know why the Zn plate becomes - (Another doubt. metals are electropositive? )and Cu plate is +?