Assuming that three factors can affect the frequency and assuming that the frequency of a open string is predetermined (for example A is 440Hz) to obtain lower tension you need to have lower mass.
More mass you add per the same length of the string more tension you need to put to obtain the same frequency.
Plain gut is the lower mass string , any wrapped strings (with copper, chrome, steel, any metal) will load more mass so more tension to put to have the same frequency.
I don't know if nylon have a specific weight more or less like gut.
More mass you add per the same length of the string more tension you need to put to obtain the same frequency.
Plain gut is the lower mass string , any wrapped strings (with copper, chrome, steel, any metal) will load more mass so more tension to put to have the same frequency.
I don't know if nylon have a specific weight more or less like gut.