Advertisements
Advertisements
प्रश्न
The diameter of a cylinder is 28 cm and its height is 20 cm. The total surface area of the cylinder is
पर्याय
2993 cm2
2992 cm2
2292 cm2
2229 cm2
उत्तर
2992 cm2
The total surface area of the cylinder = 2 πr + 2r2
= 2pi (h + r)
`= [2xx22/7xx14xx(20+14)]"cm"^2` `["d" = 28 cm => "r" = 28/2 "cm" = 14 "cm" ]`
`= 20944/7 "cm"^2`
= 2992 cm2
APPEARS IN
संबंधित प्रश्न
In a rain-water harvesting system, the rain-water from a roof of 22 m × 20 m drains into a cylindrical tank having diameter of base 2 m and height 3·5 m. If the tank is full, find the rainfall in cm. Write your views on water conservation.
A rectangular sheet of paper 40 cm × 22 cm, is rolled to form a hollow cylinder of height 40 cm. The radius of the cylinder (in cm) is ______.
Radius of a sphere is 14 cm. Find the surface area of the sphere.
The surface area of a sphere is 616 cm2 . Find its radius.
A solid metallic spherical ball of diameter 6 cm is melted and recast into a cone with diameter of the base as 12 cm. The height of the cone is
A spherical ball of diameter 21 cm is melted and recast into cubes, each of side 1 cm. Find the number of cubes so formed.
The volumes of two cubes are in the ratio 8 : 27. Find the ratio of their surface areas.
The total surface area of a cube is 864 cm2. Its volume is
The diameter of a sphere is 42 cm. It is melted and drawn into a cylindrical wire of diameter 2.8 cm. Find the length of the wire.
A factory manufactures 120000 pencils daily. The pencils are cylindrical in shape each of length 25 cm and circumference of base as 1.5 cm. Determine the cost of colouring the curved surfaces of the pencils manufactured in one day at Rs 0.05 per dm2.
