Power from Fruits!

One fine day, Professor Govind was doing some experiments on Quantum teleportation. Sheela entered his lab and found some cut fruits on the table. She thought that Govind must have cut the fruits for his breakfast. She asked, "Professor, the law is the same for all, isn't it?

"Yes, no doubt" said professor Govind.

Sheela sarcastically asked him, " Haven't you shouted at me not to eat something in the laboratory?? Then, what these freshly cut apples and lemons have to do in your laboratory?" 

Govind smiled at her and said, "Oh! These fruits are the food for these multimeters and LED's."

"Food for them!" screamed Sheela. "But how?", she asked.

"Well, I can explain you. Different types of fruits have different electrolytes(ions) in them, especially, lemons and grape fruits have acids like ascorbic acid, citric acid, ions and NADH(Nicotinamide Adenine Dinucleotide Hydride generates cellular energy). When electrodes are inserted into them, these ions migrate to the appropriate electrodes generating current.

He took an apple and inserted two electrodes, a copper electrode(cathode) on one of the sides and a Zinc rod(anode) on the other side. He connected these rods to a multimeter and it was found working. Then he replaced multimeter with an LED(Light Emitting Diode) and showed that it lit up. But the light doesn't last long. It was slowly becoming dull and finally stopped glowing.

"Oh! So, fruits produce current that won't last for even 5 minutes, yeah?? Then what's the use professor?" asked Sheela. "Hmm. Nothing, I suppose. They produce only a few current(about 2 volt) and stops as soon as all the electrolytes have been used up completely. However few more lemons connected in series can serve as our regular batteries. Also potatoes produce a few more volts than fruits. So, this is a bit economical than ours", said Professor.

"Economical?? Well, what do you mean? Don't you know that these lemons cost more than a common battery? Sound that you haven't been to the city markets, right?" laughed Sheela.

"Hmm..I didn't make a note of it. Err, I think it would help a lot in any village in an under-developed countries, where there's no availability of neither electricity nor batteries", said Govind.