Question

The ratio of the area of a smaller circle to the bigger circle is 1 : 4 . Find $\frac{\text{radius of smaller circle}}{\text{radius of bigger circle}}$.

• A. 1
• B. $\frac{1}{4}$
• C. $\frac{1}{2}$
• D. $\frac{1}{8}$

Answer 1

The correct option is C

$\frac{1}{2}$

Area = $\pi r^2$

$\frac{\text{area of smaller circle}}{\text{area of bigger circle}}=\frac{1}{4}$

If $r_1$ be the radius of the smaller circle and $r_2$ be the radius of the bigger circle

$\frac{\pi {r_1}^2}{\pi {r_2}^2}=\frac{1}{4}$

Hence $\frac{r_1}{r_2}=\frac{1}{2}$