Question

Two rings have their $M.I$ in the ratio $2:1$, If their diameters are in ratio of $2:1$, then the ratio of their masses will be:

• A. $2:1$
• B. $1:1$
• C. $1:2$
• D. $1:4$

Answer 1

The correct option is C $1:2$

$I=m{r}^2$

$m=\frac{I}{r^2}$

$\frac{m_1}{m_2}=\frac{I_1}{I_2}\frac{r_2^2}{r_1^2}$

$\frac{m_1}{m_2}=\frac{2}{1}\frac{1}{4}=\frac{1}{2}$