Surface Area of Hollow Cylinder
Surface Area of Hollow Cylinder
Hollow Cylinder: A solid bounded by two co-axial cylinders of the same height and different radii is called a hollow cylinder. Solids like iron pipes, rubber tubes etc. are hollow cylinder.
Let R and r be the external and internal radii of a hollow cylinder and h be its height as shown in the following figure.
Then we have the following results:
(i) Each base Surface Area =
(ii) Curved(Lateral) surface Area = (External surface area) + (Internal surface Area)
(iii) Total Surface Area
Illustration: Find the total surface area of the hollowed out cylinder shown in the adjacent figure.
Solution: Total surface area of hollow cylinder = Outer CSA + Inner CSA + top and bottom ringed area
Illustration: An iron pipe 20 cm long has exterior diameter equal to 25 cm. If the thickness of the pipe is 1 cm, Find the whole surface area of the pipe.
Solution: We have,
R = External radius = 12.5 cm
r = Internal radius
= (external radius - Thickness)
= 12.5 - 1
= 11.5 cm
h = length of the pipe = 20 cm
So, Total Surface Area of the Pipe = (External curved surface) + (Internal curved surface) + 2(Area of the base of the ring)
Illustration: A metal pipe is 77 cm long. The inner diameter of a cross section is 4 cm, the outer diameter being 4.4 cm. Find its
(i) inner curved surface area
(ii) outer curved surface area
(iii) total surface area
Solution: Length of the metal pipe = 77 cm(h)
Inner radius
Outer radius
(i) Inner Curved Surface Area
(ii) Outer Curved Surface Area
(iii) Total surface Area = Inner Curved surface Area + outer curved surface Area + top and bottom ringed area
The total surface area of a hollow cylinder which is open from both sides is 5024 sq cm, area of the base ring is 2452 sq cm and height 7 cm. Find the thickness of the cylinder. | |||
| Right Option : B | |||
| View Explanation | |||
Find the total surface area of the hollowed out cylinder having inner and outer radius 2 cm and 3 cm respectively and height 5 cm. | |||
| Right Option : A | |||
| View Explanation | |||
Find the total surface area of the hollowed out cylinder having inner and outer radius 8 cm and 9 cm respectively and height 10 cm. | |||
| Right Option : C | |||
| View Explanation | |||
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