Can a currency values of two countries be used to compare their richness?

Question

For eg: currently 1 USD= 42 Indian ruppees.

Is it that if in one day if 1 USD becomes 1 Indian ruppee, India is as much rich as US?

Answer 1

no way can you do that. One way to try to compare is to use purchasing parity scale used by the UN World bank

Answer 2

all other things equal, movement in currencies in the manner you have described is either a result of increased wealth by one country, a devaluation of the other's currency, or a combination of both.  you have cited an example that is hard to envision happening quickly without a major catastrophic event in the US economy, since it means things would change by a factor of 42.