Anecdotally, I have been told that the reason each home in the US has its own transformer is due to the problems of distribution.  If the 120 volts was carried distances over power lines voltage drop would be an issue.  By transforming the high voltage at each home this problem is minimised.  
 
Yep.  The power delivered to the house, which does usable work, is a simple product of voltage and current.  Double the voltage and you can halve the current.  
 
Now the current flowing through the lines to the house dissipates power according to (current)^2 times R, where R is the resistance of the lines.  Since the resistance of the lines is fixed, you halve the current and dissipate 1/4 as much power. 
 
Nat

Reply via email to