Why Frequency In some Countries is 60 Hz??

I think it is the same reason they drive on the left side of the road in some countries and on the right side in other countries!

Also I have an old book on electrical wiring for the U.S. from the early 1900's. In that book it mentions that some electricity supplied at that time was DC, some AC, and voltages from each electric company were different!

So before wiring your house, you needed to call your electric company and find out what type of electricity they had!

Then I guess they decided what worked best and did not bother to check with any other countries?

Well 50Hz or 60Hz it does not tells you shich is better.

Like in television,
50Hz is a standard used by European countries like UK, they are using SECAM and PAL... try searching the net regarding with those standards for more info.
60Hz on the other hand is used by US, and they are following the NTSC standard. It is also used in some Asian countries.

50Hz and 60Hz refers to the synchronization of power supplied and the equipment fed by the supply.

Lets say your television is using NTSC standard, that means it should be fed by 60Hz power supply. But if you supply it with 50Hz then it will not synchronize. It will not work properly or worse it will not work. But most equipment now has an automatic synchro ability, that means if your equipment detects 50Hz synch then it will still work, same with 60Hz.

Hey Friends,
Their must be something behind this.......

1.cause without technical and scientific reason they cant do this.............
Cause as they are increasing their frequency on the other hand they are reducing their voltages......

2.We are supposed to design our equipment according to our Power Supply not Power supply according to Equipment..........

3. 50Hz and 60Hz not only refers to Synchronisation But also it matters in Power and Losses............

Hey euieLC and bill190 I am not saying you are wrong but it is not satisfying My question.......
Please Provide me more information on this Topic...........I know this topic is Head AChe............But please provide me suitable ans...........

Regards,
VIPUL

@d_vipul,
Kindly view the following thread
#-Link-Snipped-#
Here, I have given a small explanation about how we determine the frequency of the supply initially, by compromising on a few factors.
I expect this explanation to satisfy the following questions.

d_vipulHey Friends,
Their must be something behind this.......

1.cause without technical and scientific reason they cant do this.............
Cause as they are increasing their frequency on the other hand they are reducing their voltages......

2.We are supposed to design our equipment according to our Power Supply not Power supply according to Equipment..........

3. 50Hz and 60Hz not only refers to Synchronisation But also it matters in Power and Losses............

Hey euieLC and bill190 I am not saying you are wrong but it is not satisfying My question.......
Please Provide me more information on this Topic...........I know this topic is Head AChe............But please provide me suitable ans...........

Regards,
VIPUL

It may be my inability to understand your words, but let me tell you, there is no direct relation between frequency and voltage, or frequency and power(for that matter). I request you to kindly view the aforesaid thread.
Thank you for showing your curiosity.