SURFACE AREAS AND VOLUMES chapter 12 exercise 12.1

SURFACE AREAS AND VOLUMES chapter 12 exercise 12.1
EXERCISE 12.1
class 10
class x

1. 2 cubes each of volume 64 cm3
are joined end to end. Find the surface area of the
resulting cuboid.
2. A vessel is in the form of a hollow hemisphere mounted by a hollow cylinder. The
diameter of the hemisphere is 14 cm and the total height of the vessel is 13 cm. Find the
inner surface area of the vessel.
3. A toy is in the form of a cone of radius 3.5 cm mounted on a hemisphere of same radius.
The total height of the toy is 15.5 cm. Find the total surface area of the toy.
4. 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.
5. A hemispherical depression is cut out from one face of a cubical wooden block such
that the diameter l of the hemisphere is equal to the edge of the cube. Determine the
surface area of the remaining solid.
6. A medicine capsule is in the shape of a
cylinder with two hemispheres stuck to each
of its ends (see Fig. 12.10). The length of
the entire capsule is 14 mm and the diameter
of the capsule is 5 mm. Find its surface area.
SURFACE AREAS AND VOLUMES
7. A tent is in the shape of a cylinder surmounted by a conical top. If the height and
diameter of the cylindrical part are 2.1 m and 4 m respectively, and the slant height of the
top is 2.8 m, find the area of the canvas used for making the tent. Also, find the cost of
the canvas of the tent at the rate of ` 500 per m2
. (Note that the base of the tent will not
be covered with canvas.)
8. From a solid cylinder whose height is 2.4 cm and diameter 1.4 cm, a conical cavity of the
same height and same diameter is hollowed out. Find the total surface area of the
remaining solid to the nearest cm2
.
9. A wooden article was made by scooping
out a hemisphere from each end of a solid
cylinder, as shown in Fig. 12.11. If the
height of the cylinder is 10 cm, and its
base is of radius 3.5 cm, find the total
surface area of the article.