Why the voltage is different everywhere?

This is a VERY complicated question and gets more things than voltage (it's a three-step voltage/frequency). But let's get back to why do we have (220/230/240/110/100 volts). The simple answer is the more voltage you have (220 let's say) the less material (copper) you need to transmit the current. The lower the voltage the more material (copper) you need to move the current. The higher the voltage, the more dangerous. The lower the voltage, the less dangerous. The higher the voltage the faster a light bulb will burn out. The lower the voltage the longer a filament bulb will last. This goes all the way back to the early days of electricity and two men with two differing ways of supplying electric (Edison with direct current [DC] and Tesla with alternating current [AC]). Alternating current won out over Direct. Tesla wins. Lower voltage won out (in US) over higher voltage. Edison wins. It is a very intriguing subject and something I can't write enough about but something you may want to read about on the internet further! Thanks. Zelo PS. US households have both 110 and 220 in their house. The plugs in the house are 110 but to use a clothes dryer there needs to be more power to create all the heat and the air conditioner needs power to create cold. These are hooked into 220 power. You are going to see more 220 plugs in the US as well when electric cars become more popular. Recharging a car with 110 power can take 8 hours where with 220 it can take as little as 3 hours.

Yes there is a difference depending on what country one is in. Here in the US ours is 110 and I know my boyfriends little one lives in England she cannot use the same electronics here that she uses there. We have had to buy adapters and still with some of them she still can't use them there.

A good point you're raising there...it would be useful to have standardised mains voltage wherever you go..Some countries just went with one standard because it was something that worked for them at the time..UK Mains voltage would be 220/240v,so you can buy travel transformers to use US voltage mains gadgets here...a lot of smaller gadgets can use USB charger sockets,so that makes things a little easier now..

In my home country we have 240v and so when I went to Canada the voltage was 110v. My net book can cope with either voltage however I bought a DVD player in Canada and it needs to have something which works with the voltage 110v. I bought a transformer for it and so it works fine in my home country using this. Electrical plugs come in different types. In my home country we have three pins and the American plug has two pins. In Canada I managed to get a little box that can give me plugs for anywhere in the world. The options are the Americas, the UK, Europe, Australasia and Asia. I wish the voltage were the same worldwide and the electrical plugs were universal. As a keen traveler the different voltage can give me problems.

I have also discovered this from the foreign teachers working in our school. In Japan, it is also 110v. But it is a big problem for them to use our voltage here as they have something like a transformer. Also if you travel to those countries with a different voltage, I am sure that there must be some way out for you. Enjoy yourself, youless.

hi youless, here in korea we used 220v