My teacher gave us a few homework questions regarding on arranging oxidizing agents on their strengths. I can tell if it's strong or weak if it's on a table... However, there's a question where we have to arrange it based on the voltage it produced??

For example:

Reduction reaction Oxidation reaction Resulting voltage
Cu+2 + e- --> Cu+ Pb ---> Pb+2 + 2e- 0.11V
Cu+2 + e- --> Cu+ Ni ---> Ni+2 + 2e- 0.05V
Cu+2 + e- --> Cu+ Fe ---> Fe+2 + 2e- 0.09V

Can someone explain to me how to do it?? Thank you!

Voltage is essentially the electrical energy potential, a higher voltage would mean there was a larger difference between your reducing and oxidising reagent. If this is the case which do you think would be the strongest oxidiser?