Tamil Nadu Board of Secondary EducationSSLC (English Medium) Class 10th
Advertisement Remove all ads

The height and radius of the cone of which the frustum is a part are h1 units and r1 units respectively. Height of the frustum is h2 units and the radius of the smaller base is r2 units. If h2 : h1 - Mathematics

Advertisement Remove all ads
Advertisement Remove all ads
MCQ

The height and radius of the cone of which the frustum is a part are h1 units and r1 units respectively. Height of the frustum is h2 units and the radius of the smaller base is r2 units. If h2 : h1 = 1 : 2 then r2 : r1 is

Options

  • 1 : 3

  • 1 : 2

  • 2 : 1

  • 3 : 1

Advertisement Remove all ads

Solution

1 : 2

Explanation;

Hint:

h2 : h1 = 1 : 2

h1 : h2 = 2 : 1

Ratio of their volumes

= `1/3 pi"h"_1 ("r"_1^2 + "r"_2^2 + "r"_1"r"_2) : 1/3pi"h"_2 ("r"_1^2 + "r"_2^2 + "r"_1"r"_2)`

= 2(r12 + r22 + r1r2) : 1 (r12 + r22 + r1r2)

Volume is 2 : 1 the ratio of their radius also 2 : 1

r1 : r2 = 2 : 1 But r2 : r1 = 1 : 2

Concept: Volume of Frustum of a Cone
  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

Tamil Nadu Board Samacheer Kalvi Class 10th SSLC Mathematics Answers Guide
Chapter 7 Mensuration
Exercise 7.5 | Q 14 | Page 298
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×