Question

What is the diameter (in cm) of a sphere whose surface area is 616 $c{m}^2$?

• A. 12 cm
• B. 18 cm
• C. 10 cm
• D. 14 cm

Answer 1

The correct option is D

14 cm

The surface area of a sphere of radius $r$ is given by $4\pi r^2$.
Given, $4\pi r^2=616c{m}^2$
$⟹r^2=616\times \frac{7}{22}\times \frac{1}{4}$
$⟹r^2=49$
$⟹r=\sqrt{49}$
$⟹r=7cm$

$\therefore \text{Diameter}=2r=2\times 7=14cm$