Yes, it will work just fine. In the United States the voltage coming into homes and businesses is 240 volts but the term 220 volts is commonly used but they essentially mean the same thing.
Yes, it can be and there is no problem at all Because most of the electrical appliances are made to work on 220v - 240v so it can also be plugged into a 240v outlet.
yes.
Most appliciances that are built for use with 220V would normally be fine with 240V. In most cases, they are also labeled 220-240V. Depending on how critical the application is, you should probably check with the manufacturer.
It should work fine, you'll just get a less power dissipated (and therefore heat) than you're expecting.
Off hand no but your explanations are not clear as to who is doing what to whom,,
There will be no problems as the Mac laptops are designed to work internationally with a line voltage ranging from 100V to 240V.
no, you'll probably get electrocuted
you do NOT put two 110v breakers in. you put 1 two pole breaker in. the panel is designed to give you 220v off one side OR the other side if you use a 2 pole breaker on one side or the other side. If you look at both 120V lines on an oscilloscope you will notice that they are both 120V to the neutral, but they are 180 degrees out of phase. This means that when one hot is at +120V the other is at -120V. So between the two you have 240V. If you put your meter across both hots you should see 240V. If you do not see 240V across both hots you (or an unlicenced electrician) has wired the outlet without using a proper 220V breaker. You do not see 240V because the hots are in phase, to the voltage differential is 0V, not 240V. 220V breakers cannot do this, unless forcebly installed in the wrong type panel. More than likely someone tried to wire it with 110V breakers.
I guess it will, but it depends on the type of device you use. An electric bulb may glow with reduced intensity at the same time, a regulated psu based device may balance the voltage by drawing required amount of current to bring it to 240V inside the psu unit of that device. It again depends upon the device. Some devices use some range of input operating voltages like 220V ~ 240V.I guess I'm right
There will be no problems as the Mac laptops are designed to work internationally with a line voltage ranging from 100V to 240V.
This is not a DIY project. When lives are involved the best bet is to get a qualified electrician to permit and do the job.
Do you mean a 220V as in a power in Europe? Then,Check your adaptor. It will tell you the input voltage. If it sates that the range of the input voltage in 100V-240V then YES you can plug in your adapter into a 220V outlet.Please note that some people advise that you plug in the adapter into the power before plugging it into the computer.