50 Hz and 60 Hz is frequency of Alternative Current was developed by Nikola Tesla
Alternative Current generator start at Niagara Falls in 1893 to 1896.
after the World War II, Germany and
Korea
was divided in two section.
Japan was divided in two section in
electric
world at Nagano and Yamanashi.
Germany unification in 1989, and Korea
may will soon, but i don't know for Japan.
NAGANO & YAMANASHI
