Question

why to always take us dollar as a core measurement why not currency of our nation or other is not use for exchange rate purpose.
is America king of this universe

Answer 1

There are no restriction on the convertibility of US dollar to any currency in the international market. This implies that the dollars are fully convertible in the international market. On the other hand, Indian rupee is partially convertible to an extent i.e it cannot be converted into other countries in a restriction less manner.

This is the prime reason that exchange rate is measured in US dollars. Also, the currency of US is more stable as compared to other countries.