The ratio of the surface area of a sphere and the curved surface area of the cylinder circumscribing the… · ABC26GN5029
Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: C.P.O. 2006
The ratio of the surface area of a sphere and the curved surface area of the cylinder circumscribing the sphere is
(a)1 : 1
(b)1 : 2
(c)2 : 1
(d)2 : 3
Answer
Answer (as printed): A
Explanation
Let the radius of the sphere be $r$. Then, radius of the cylinder $=r$. height of the cylinder $=2 r$. Surface area of sphere $=4 \pi r^{2}$. Surface area of the cylinder $=2 \pi r(2 r)=4 \pi r^{2}$. ∴ Required ratio $=4 \pi r^{2}: 4 \pi r^{2}=1: 1$.
Explanation as extracted from the printed page; notation may be imperfect.