Question

The ratio of the total surface area of a sphere to that of a hemisphere when they have the same radius is

• A. 4:3
• B. 3:4
• C. 3:2

Answer 1

The correct option is A 4:3

We know that,

$Totalsurfaceareaofsphere=4\pi r^2$
$Totalsurfaceareaofhemisphere=3\pi r^2$

Now,
$=\frac{Totalsurfaceareaofsphere}{Totalsurfaceareaofhemisphere}$
$=\frac{4\pi r^2}{3\pi r^2}$
$=\frac{4}{3}$
$=4:3$

$\therefore$ The ratio between the total surface area of the sphere and that of the hemisphere is 4:3.