Question

Why electric supply in india is only 50 hz why not 60 hz

Answer 1

It is an optimum frequency like Prototype said, you cannot use >60Hz.

And 50Hz is not fixed, it's not universal frequency.

United states & many Europe countries uses 60Hz frequency which is close optimum frequency to 50Hz.

However, it has been noticed that lower frequencies causes the size, weight & hence the cost to increase. Also, more flickers are noticed in lesser frequencies than higher frequencies. Hence 60Hz is preferred over 50Hz in most developed countries.

Both frequencies have drawbacks & Pros.

Some countries switched to 50Hz just to fit the metric system.

PS: countries with 60Hz frequency dont use 220V/240V Power supply, infact 110V-120V supply is used