Let IA and IB be moments of inertia of a body about two axes A and B respectively. The axis A passes through the centre of mass of the body but B does not.

We know the parallel axis theorem states that –


“The moment of inertia of a body about an axis parallel to an axis passing through the centre of mass is equal to the sum of the moment of inertia of body about an axis passing through centre of mass and product of mass and square of the distance between the two axes”



Where


r is the distance between the parallel axes.


Hence we can say that IA < IB.

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