Use principle of homogenity of dimensions to find which one of the following relations is correct : (i) `T^2 =4pi^2r^2`
(ii) `T^2 =(4pi^2r^3)/(G)`
(iii) `T^2 = (4pi^2 r^3)/(GM)`

Explanation

Only relation (iii) is correct is
`(4pi^2r^3)/(GM) = (L^3)/(M^(-1)L^3 T^(-2)M) = T^2`