The radii of a frustum of a cone are $10\,cm$ and $7\,cm$. If its height is $4\,cm$, then its curved surface area is $\ldots \ldots \ldots \,cm^2$. (in $\pi$)

$A$ medicine capsule is in the shape of a cylinder of diameter $0.5\, cm$ with two hemispheres stuck to each of its ends. The length of the entire capsule is $2\, cm$. The capacity of the capsule is (in $cm^3$):

$A$ metallic sphere with diameter $12 \, cm$ is melted and identical balls with radius $0.3 \, cm$ are produced. Find the number of balls produced.

Write 'True' or 'False' and justify your answer:
The actual capacity of a vessel as shown in the figure is equal to the difference between the volume of the cylinder and the volume of the hemisphere.

The radius and height of a cylinder are $1.4 \, cm$ and $10 \, cm$ respectively. Then,its curved surface area is $\ldots \ldots \ldots \, cm^2$.

In a right circular cone,the cross-section made by a plane parallel to the base is a