Advertisements
Advertisements
प्रश्न
Find the surface area of a sphere of radius 10.5 cm.
`["Assume "pi=22/7]`
Advertisements
उत्तर
Radius (r) of sphere = 10.5 cm
Surface area of sphere = 4πr2
= `[4xx22/7xx(10.5)^2] cm^2`
= `(4xx22/7xx10.5xx10.5) cm^2`
= (88 × 1.5 × 10.5) cm2
= 1386 cm2
Therefore, the surface area of a sphere having a radius of 10.5 cm is 1386 cm2.
APPEARS IN
संबंधित प्रश्न
A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of ₹ 16 per 100 cm2.
`["Assume "pi=22/7]`
A solid sphere of radius 15 cm is melted and recast into solid right circular cones of radius 2.5 cm and height 8 cm. Calculate the number of cones recast.
Find the surface area of a sphere of radius 10.5 cm.
Find the surface area of a sphere of radius 5.6 cm.
Find the total surface area of a hemisphere and a solid hemisphere each of radius 10 cm.
(Use 𝜋 = 3.14)
The dome of a building is in the form of a hemisphere. Its radius is 63 dm. Find the cost of painting it at the rate of Rs. 2 per sq. m.
A cylinder of same height and radius is placed on the top of a hemisphere. Find the curved
surface area of the shape if the length of the shape be 7 cm.
A wooden toy is in the form of a cone surmounted on a hemisphere. The diameter of the base
of the cone is 16 cm and its height is 15 cm. Find the cost of painting the toy at Rs. 7 per 100
`cm^2`.
The diameter of a sphere is 6 cm. It is melted and drawn into a wire of diameter 0.2 cm. Find the length of the wire.
The surface area of a sphere of radius 5 cm is five times the area of the curved surface of a cone of radius 4 cm. Find the height of the cone.
A sphere and a cube are of the same height. The ratio of their volumes is
If the radius of a solid hemisphere is 5 cm, then find its curved surface area and total surface area. ( π = 3.14 )
Find the surface area of a sphere, if its volume is 38808 cubic cm. `(π = 22/7)`
How many lead balls of radii 1 cm each can be made from a sphere of 8 cm radius?
Find the volume and surface area of a sphere of diameter 21 cm.
A sphere cut out from a side of 7 cm cubes. Find the volume of this sphere?
The internal and external diameters of a hollow hemispherical vessel are 20 cm and 28 cm respectively. Find the cost to paint the vessel all over at ₹ 0.14 per cm2
A solid sphere is cut into two identical hemispheres.
Statement 1: The total volume of two hemispheres is equal to the volume of the original sphere.
Statement 2: The total surface area of two hemispheres together is equal to the surface area of the original sphere.
Which of the following is valid?
