Question

A circular dis is to be made by using iron and aluminum so that it acquired maximum moment of inertia about geometrical axis.It is possible with?

Answer 1

It is possible with Aluminium at interior and iron surrounding it
REASON
Moment of inertia = MR^2
Now, the atomic mass of iron is much greater than the atomic mass of aluminium and thus for moment of inertia to be maximum, Iron should be placed furthur away from the geometrical axis and aluminium should be placed closer to it.
So, the Aluminium at interior and iron surrounding it.
You will come across more accurate and theoritcal solution with some complicated theories in your higher studies