Consider the equation `T = 2pi sqrt(l/g)` and check whether it is correct or not.

Explanation

We know, dimensional formula of T, l and g are [T], [L], `[LT^(-2)]` respectively.
`therefore` Dimensional formula of `sqrt((l)/(g)) = sqrt((L)/(LT^(-2)))= sqrt(T^(2))= [T]`
Dimensional formula of left side is also [T]. As `2pi` is a dimensionless quantity, the dimensional formula of left hand side of the equation is equal to dimensional formula of right hand side. Hence we conclude that the given equation is a correct one.