class 10 mesuration sphere Ex 6.2

6.2 9:40 PM

Saturday, January 30, 2021

Some formulas

curved surface area of hemi -sphere=

Total surface area of hemisphere =

volume of hemisphere =
if sphere or hemisphere are melt then only volume is same

4a) if the circumference of a great circle of a hemisphere is Find its volume
solution:
circumference ( c) =

volume of the Sphere ( V )=

5a) the total surface area of the hemisphere is
solution:
Total surface area of the hemisphere =

r=4
Volume of the hemisphere =

=

6a) surface area of the sphere is 5544 . Find the volume of the sphere
solution :
Surface area of the Sphere =

5544=

r=
volume of the sphere( V)=

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7a) A solid metallic sphere of radius 7 cm is cut into two half . Find the total surface
area of the two hemisphere so formed .
Solution:
Radius of sphere ( r )=7 cm
TSA of hemisphere =

=3

8) there are two sphere objects made of clay having the same shape and size. If the total
surface area of one hemisphere objects is 462 , find the total surface area of the sphere
which is formed by attaching those two hemispherical object
Solution :
T SA of hemisphere(
T SA of sphere=

=
=

9) the surface area of sphere is equal to the area of curved surface of a right circular
cylinder . If the height and diameter is 16 cm each find the diameter of the sphere.
solution :
Height of cylinder (h)= 16
Diameter (d)=16
Radius ( r)= 8
CSA if cylinder=

=
=

the surface area of sphere is equal to the area of curved surface of a right circular
cylinder

the surface area of sphere = area of curved surface of a right circular cylinder

10) The ratio of surface area and volume of sphere are in the ratio of 3:7 cm what is the
circumference of its great circle and volume? Find it

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circumference of its great circle and volume? Find it
Solution:
Ratio of surface area and volume of sphere are in the ratio of 3:7

r=3
circumference( C ) =
volume of sphere(V)=
11) A solid sphere of radius 18 cm is melt and down and drawn out into a long cylinder
6 mm thickness find the length of wire
solution :
Radius of spere : 18
Volume of Sphere( V)=
radius of cylinder (r1)= 0. 3 cm
volume of cylinder= volume of sphere

12) three iron sphere having radius 6 cm 8 cm 10 cm are melted to form new sphere .
Find the radius of new sphere
Solution :
let be the radius of three sphere and R be the radius of the new sphere
volume of three sphere is equal to volume of new sphere

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