Four point masses, each of value m, are placed at the corners of a square ABCD of side l. The moment of inertia of this system about an axis passing through A are parallel to BD is :

Options

A. `2m//l^(2)`
B. `sqrt(3)ml^(2)`
C. `3ml^(2)`
D. `ml^(2)`

Answer

C

Explanation

`I_(LM)=m_(A)(0)^(2)+m_(B)((lsqrt(2))/(2))^(2)+m_(C)(lsqrt(2))^(2)+m_(D)((lsqrt(2))/(2))^(2)`
`I_(LM)=0+(ml^(2))/(2)+2ml^(2)+(ml^(2))/(2)=3ml^(2)`