What would be a good hypothesis for the problem statement what citrus fruit can produce the highest volts?

Question

the fruits are oranges, tangerines, grapefruits, and limes

Answer 1

Null hypothesis:

There is no significant difference in the electrical voltage produced by orange, tangerine, grapefruit and lime extracts.

(Tip: Subject your data to statistical data analysis using the One Way ANOVA, and bingo! You'll impress your research teacher!)

Answer 2

I know there's some online research, but I don't remember where I found it.  My kids had to do an electricity project and we did a circuit with lemons.  Something about the high acidity in the fruit reacted with the copper to be an electricity conductor.