Question

If the height of a sphere is 20 cm, then the total surface area of the sphere is

• A. $800\pi c{m}^2$
• B. $1600\pi c{m}^2$
• C. $400\pi c{m}^2$
• D. $600\pi c{m}^2$

Answer 1

The correct option is C $400\pi c{m}^2$

Let $r$ be the radius of the sphere.

Since, height of the sphere is 20 cm.
$\therefore 2r=20cm$
$\Rightarrow r=10cm$
∴ TSA of sphere $=4\pi r^2$
$=4\pi \times (10{)}^2$
$=400\pi c{m}^2$
Hence, the correct answer is option (c).