If the moment of inertia of a section about its axis is l and its effective sectional area is A, its radius of gyration r about the axis is
1
r = I/A
2
r = √(I/A)
3
r = √(A/I)
4
None of these
If the moment of inertia of a section about its axis is l and its effective sectional area is A, its radius of gyration r about the axis is