A right circular cylinder just encloses a sphere of radius r (see figure). Find
(i) surface area of the sphere,
(ii) curved surface area of the cylinder,
(iii) ratio of the areas obtained in (i) and (ii).
(i) Surface area of sphere = 4πr2
(ii) Height of cylinder = r + r = 2r
Radius of cylinder = r
CSA of cylinder = 2πrh
= 2πr (2r)
`"Required ratio "="Surface area of sphere"/"CSA of cylinder"`
`= (4pir^2)/(4pir^2)= 1/1`
Therefore, the ratio between these two surface areas is 1:1.
Video Tutorials For All Subjects
- Surface Area of a Sphere