Question

1/f=1/P +1/q is dimensionally correct

Answer 1

1 /f = 1 /p + 1 /q

The following equation is dimensionally correct because only physical quantities of same dimension can be added together i.e.

       Dimension of 1 /p and 1 /q are same.

Two physical quantities of same dimension when added together gives a physical quantity with the same dimension as that of the added quantities i.e

       Dimensions of 1 /p, 1 /q and 1 /f are the same