The radius of a sphere is equal to the radius of the base as well as the height of a right circular cylinder. What is the ratio of surface area of sphere and curved surface area of cylinder respectively?

2 : 1

We know that,

The radius of the sphere = r

The radius of cylinder = R

Height of cylinder = h

Surface area of sphere = 4π r²

The curved surface area of the cylinder = 2πRh 

According to the question,

r = R = h

Curved surface area of cylinder = 2 × π × R × h = 2 × π × r × r = 2π r²

The surface area of the sphere: Curved surface area of cylinder = 4π r² : 2π r² = 2: 1