Solution:
Solution
The moment of inertia is given as,
$$I = \frac{2}{5}M{R^2}$$
$$I = \frac{2}{5} \times \frac{4}{3}\pi {R^3} \times \rho \times {R^2}$$
$$I \propto {R^5}$$
$$\frac{{{I_1}}}{{{I_2}}} = {\left( {\frac{{{R_1}}}{{{R_2}}}} \right)^5}$$
The ratio of moments of inertia about their diameters is given as,
$$\frac{{{I_1}}}{{{I_2}}} = {\left( {\frac{2}{1}} \right)^5}$$
$$\frac{{{I_1}}}{{{I_2}}} = \frac{{32}}{1}$$