Four thin metal rods, each of mass `M` and length `L`, are welded to form a square `ABCD` as shown in figure. The moment of inertia of composite structure about a line which bisects rods `AB` and `CD` is

Options

A. `(ML^(2))/6`
B. `(ML^(2))/3`
C. `(ML^(2))/2`
D. `(2ML^(2))/3`

Answer

D

Explanation

`I=I_(1)+I_(2)+I_(3)I_(4)`
`I_(1)=I_(2)=(ML^(2))/12` and `I_(3)=I_(4)=M[L/2]^(2)`