Math, asked by prachisahoo2, 6 months ago

13. If a circle and a sphere have same
radii, then the ratio between the area
of the circle to the surface area of
the sphere is *
O 1:4
O 4:1
O 1:1
none of these​

Answers

Answered by prevanth1507
0

ANSWER

Since, the height of a sphere is the diameter, the cone and cylinder have height 2r.  

Then  

Curved surface area of Sphere=4πr²

Curved surface area of cylinder =2πr(2r)=4πr²

Curved surface area of cone = πrl

where, l=  

(r  

2

+h  

2

 

​  

)=  

(r2+(2r)  

2

 

​  

)=  

5r  

2

 

​  

=r  

5

​  

 

⇒ Curved surface area of cone =π  

5r  

2

 

​  

 

Now,  

ratio of CSA 's a sphere ,cylinder and a cone = 4πr  

2

:2πrh:πrl

=4πr  

2

:4πr  

2

:πr  

2

 

5

​  

 

=4:4:  

5

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