Surface area of a sphere $= \dots \dots \dots \dots .$

Write 'True' or 'False' and justify your answer:
$A$ solid cone of radius $r$ and height $h$ is placed over a solid cylinder having the same base radius and height as that of the cone. The total surface area of the combined solid is $\pi[\sqrt{r^{2}+h^{2}}+3r+2h]$.

Write 'True' or 'False' and justify your answer:
The curved surface area of a frustum of a cone is $\pi l(r_{1}+r_{2})$,where $l = \sqrt{h^{2}+(r_{1}+r_{2})^{2}}$,$r_{1}$ and $r_{2}$ are the radii of the two ends of the frustum,and $h$ is the vertical height.

The $TSA$ (Total Surface Area) of a $5$-rupee coin is given by the formula $\ldots \ldots \ldots . .$

$A$ toy is in the form of a cone of radius $3.5 \, cm$ mounted on a hemisphere of the same radius. The total height of the toy is $15.5 \, cm$. Find the total surface area of the toy (in $cm^2$). $\left[ \text{Use } \pi = \frac{22}{7} \right]$

$A$ cubical block of side $7 \, cm$ is surmounted by a hemisphere. What is the greatest diameter the hemisphere can have? Find the surface area of the solid (in $cm^2$). [Use $\pi = \frac{22}{7}$]