Question

How to generate electricity using apples.

Explain why electricity gets generated in an apple.

:)

Answer 1

well, this reminds me of an activity I did during my 6th grade, but it was done using lemons. I hope the similar works with apples too. Basically, it's all about constructing a circuit.
So, answer for the q "How?"- 
Things you'll need:
Apples (4-5)
An LED or other low power electrical output A galvanized (zinc) Nail for the negative electrode
A piece of copper wire or a copper Penny for the positive electrode Connecting wires
A multimeter or a voltmeter to measure output

Working:

The copper serves as the positive electrode or cathode and the galvanized (zinc coated) nail as the electron-producing negative electrode or anode. These two objects work as electrodes, causing an electrochemical reaction which generates a small potential difference.

Since copper (Cu) atoms attract electrons more than zinc (Zn) atoms, if you place a piece of copper and a piece of zinc in contact with each other, electrons will pass from the zinc to the copper. As the electrons concentrate on the copper they will repel each other and stop the flow of electrons from zinc to copper. On the other hand, if you put strips of zinc and copper in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution will allow the electrons to flow continuously through the wire.

Why- An apple battery is made with an apple and two metallic electrodes of different metals such as a copper penny or wire and a galvanized (zinc coated) nail.

The energy for the battery does not come from the lemon, but rather the chemical change in zinc (or other metal). The zinc is oxidized inside the apple, exchanging some of its electrons in order to reach a lower energy state, and the energy released provides the power. The apple merely provides an environment where this can happen, but they are not used up in the process.

Assuming that zinc and copper electrodes are used (such as a copper coin and a zinc plated nail) then a single apple could generate approximately 0.9 Volts. To the left a series circuit of lemons shows 3.41 volts being produced.

Suggestion: Use a lemon instead of an apple.

Reason: Because of their higher acidity. In potatoes, for instance, the electrolyte is phosphoric acid, while in lemons it is citric acid.