Question

A circular disc is to be made by using iron and aluminium so that it possesses maximum moment of inertia about geometrical axis. It is possible with:

• A. Aluminium at interior and iron surrounding it
• B. Iron at interior surrounded by aluminium
• C. Using iron and aluminium layers in alternative order
• D. None of these

Answer 1

The correct option is A Aluminium at interior and iron surrounding it

Moment of inertia is depends on distribution of mass about axis of rotation.Density of iron is more than that of aluminium, therefore for moment of inertia to be maximum, the iron should be far away from the axis. Thus, aluminium should be at interior and iron surrounds it.