Math – Class 9 | NCERT

Class 9 | Chapter 13 | Surface areas and Volumes | Exercise 13.4 | Question 9

Question 9: A right circular cylinder just encloses a sphere of radius r (see Fig. 13.22). Find surface area of the sphere curved surface area of the cylinder ratio of the areas obtained in (i) and (ii) Question 8 Ex:…

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Class 9 | Chapter 13 | Surface areas and Volumes | Exercise 13.4 | Question 8

Question 8: A hemispherical bowl is made of steel, 0.25 cm thick. The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl. Question 7 Question 9

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Class 9 | Chapter 13 | Surface areas and Volumes | Exercise 13.4 | Question 5

Question 5: A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of ` 16 per 100 cm2. Question 4 Question 6

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Class 9 | Chapter 13 | Surface areas and Volumes | Exercise 13.4 | Question 4

Question 4: The radius of a spherical balloon increases from 7 cm to 14 cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases. Question 3 Question 5

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