Question

answer whether u know

Answer 1

Answer : Option(B) 4:4:√5,

Here is the solution :

Given that,

A sphere, A cylinder and A cone have same radius and Height !.

We need to find Ratio of Curved Surface Area !.

Let Radius of Sphere = R of Cylinder = R of Cone = r ,

Height of Sphere = Diameter of Sphere = 2r,

From Question,

Height of cylinder and Cone = 2r,


Curved surfaces areas :

(1) C.S.A of Sphere : 4πr², = 4πr²
(2) C.S.A of Cylinder = 2πrh, = 4πr²
(3) C.S.A of Cone = πrl

l = slant height = √(r²+h²) => l = √(5r²) => (√5)r
=> (3) C.S.A of Cone = √5 πr²

=> Ratio of C.S.A of Sphere : C.S.A of Cylinder : C.S.A of Cone is,

=> 4πr² : 4πr² : √5 π r²

Cancelling πr²,

=> Ratio is 4 : 4 : √5,

Therefore : Hence proved that Ratio of C.S.A of Sphere : C.S.A of Cylinder : C.S.A of Cone = 4:4:√5 ,

Hope you understand, Have a Great day !.
Thanking you, Bunti 360 !..