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 and parallel to BD is

Options

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

Answer

B

Explanation

MOI of the system about given axis
`I=I_(1)+I_(2)+I_(3)+I_(4)`

`implies I=0+m(r_(2))^(2)+m(r_(3))^(2)+m(r_(4))^(2)`
`=m((1)/(sqrt(2)))^(2)+m(lsqrt(2))^(2)+m(l//sqrt(2))^(2)impliesI=3ml^(2)`