Why the voltage of electric current is measured in multiple of eleven

I'm planning an extended trip to 220V country and have all dual voltage electronics. I'd like to bring an extension cord and current tap (light socket with additional outlets). Are these designed for specific voltages or is the voltage concern only in the appliance itself? I cannot find one that...

Hey I am doing a project on resistance.it is called to investage the relationship between the length of a metallic conductor and its resistance.could I please get any information on this as possible.. tanks

Why metal conduct electricity rather than a wood?THANK YOU!

Hi! :) I'm doing a GCSE coursework and could you please give me a very detailed explanation of how resistance is caused in a wire (constantan wire) as its length is increased;why the resistance increases. Thank you so much :-*