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A Cone and a Hemisphere Have Equal Bases and Equal Volumes the Ratio of Their Heights is

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Question

A cone and a hemisphere have equal bases and equal volumes the ratio of their heights is

Options

  • 1 : 2

  •  2 : 1

  • 4 : 1

  • \[\sqrt{2}\] : 1

     

MCQ
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Solution

In the given problem, we are given a cone and a hemisphere which have equal bases and have equal volumes. We need to find the ratio of their heights.

So,

Let the radius of the cone and hemisphere be x cm.

Also, height of the hemisphere is equal to the radius of the hemisphere.

Now, let the height of the cone = h cm

So, the ratio of the height of cone to the height of the hemisphere = `h/x`

Here, Volume of the hemisphere = volume of the cone

`(2/3) pi r_h^3 = (1/3) pi r_c ^2 h `

`(2/3) pi (x)^3 = (1/3) pi (x)^2 h`

`(2/3) (x) = (1/3) h`

         `2x = 1h`

       `h/x = 2/1`

Therefore, the ratio of the heights of the cone and the hemisphere is 2 : 1.

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Chapter 21: Surface Areas and Volume of a Sphere - Exercise 21.4 [Page 27]

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R.D. Sharma Mathematics [English] Class 9
Chapter 21 Surface Areas and Volume of a Sphere
Exercise 21.4 | Q 14 | Page 27

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