Lateral Surface Area of Hollow Cylinder
Lateral 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)
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
Solution: Length of the metal pipe = 77 cm(h)
Inner radius
Outer radius
(i) Inner Curved Surface Area
(ii) Outer Curved Surface Area
Illustration: Find the outer and inner curved surface area of the hollowed out cylinder shown in the adjacent figure.
Solution: Height of the cylindrical pipe is 77 cm. Inner diameter = 4 cm. So, inner radius = 2 cm. Outer diameter = 4.4 cm. So, outer radius = 2.2 cm
Find the lateral surface area of the hollow cylinder if inner and outer radii are 3 cm, 4 cm respectively and height is 14 cm. | |||
| Right Option : B | |||
| View Explanation | |||
Find the lateral surface area of the hollow cylinder if inner and outer radii are 4 cm, 7 cm respectively and height is 7.7 cm. | |||
| Right Option : C | |||
| View Explanation | |||
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 outer curved surface area. (in sq cm) | |||
| Right Option : D | |||
| View Explanation | |||
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