Question

The diameter of a sphere whose surface area is $346.5$ ${cm}^2$ is:

• A. $5.25$ $cm$
• B. $5.75$ $cm$
• C. $11.5$ $cm$
• D. $10.5$ $cm$

Answer 1

The correct option is A $5.25$ $cm$

Let radius of sphere be $r$ cm.

Given, the surface area of a sphere $=346.5{\text{cm}}^2$.

We know, surface area of sphere $=4\pi r^2$.

$4\pi r^2=346.5c{m}^2$

$r^2=\frac{346.5}{4\pi }$

$=\frac{346.5\times 7}{4\times 22}$

$=\frac{2425.5}{4\times 22}$

$=27.5625$

$⟹$ $r=\sqrt{27.5625}=5.25\text{cm}$ .

Therefore, option $A$ is correct.