# Civil Engineering - Strength of Materials - Discussion

### Discussion :: Strength of Materials - Section 1 (Q.No.29)

29.

The ratio of the moment of inertia of a circular plate and that of a square plate for equal depth, is

 [A]. less than one [B]. equal to one [C]. more than one [D]. equal to 3π/16 [E]. none of these.

Explanation:

For circular plate, MI = π*d^4/64.

For square plate, MI = d^4/12.

So, Ratio = MI of circular plate/MI of square plate.

= 3*π/16.

 Abhay said: (Feb 2, 2016) For circular plate Moment of inertia Ic = πD^4/64. For square plate Moment of inertia is = D^4/12. Ratio = (πD^4/64)/( D^4/12) => 3π/16.

 Himzz said: (Nov 24, 2016) According to me, it seems option A is also right.

 Roop Kumar said: (Mar 2, 2018) Both options D & A are correct.

 Parmanand Prasad said: (May 5, 2018) Both A and D is correct.

 Gnanasundar said: (Sep 5, 2018) The Answer should be 3π/16. M.O.I of circular=πD^4/64, M. O. I of rectangular=D^3/12, But here depth is given equal so M. O. I of rec=D^4/12, Circular/rectangular =3π/16.

 Amarjreet Kumar said: (Aug 18, 2019) According to me, A is the right option.