Question

why dimensional methods are applicable only up to three quantities?

Answer 1

❤️If a quantity depends on more than three factors having dimensional formula cannot be derived Because on equating the powers of M,L,&T on either side of the dimensional equation,three equations can be obtained,from which only three unknown dimensions can be calculated. ❤️

Answer 2

They are expressed in the form of mass M, length L, and time T. Almost all the physical quantities can be expressed in these three dimensions itself. Also when three dimensions are involved only three equations shall be enough to solve. If the number of unknown quantities increases it becomes a bit hard to solve.