Question

If a commodity is provided free to public then what is its opportunity cost

Answer 1

A free good is a product that is not scarce, and therefore it is available without having any limit.

A free good is available in abundance and in great quantity which comes with zero opportunity cost to the society.

So, a product which is a free good is not necessarily a free good.

When economists refer to the word "opportunity cost" of a resource or a good, they often mean the value of the next highest valued alternative use of that resource.