class 9 maths chapter 13 exercise 13.4

ncert class 9 maths chapter 13 solution, Surface Areas and Volumes Exercise 13.4 involve complete  answers for each question in the exercise 13.4. The solutions provide students a strategic methods  to prepare for their exam. Class 9 Maths Chapter 13 Surface Areas and Volumes exercise 13.4 questions and answers helps students to perform better in exam and it will  clear doubts definitely. Students will find it extremely easy to understand the questions and learn solving the problems. NCERT Solutions for Class 9 Maths Chapter 13 Surface Areas and Volumes prepared by www.mathematicsandinformationtechnology.com team in very delicate, easy and creative way. 

1. Find the surface area of a sphere of radius:
(i) 10.5 cm (ii) 5.6 cm (iii) 14 cm

2. Find the surface area of a sphere of diameter:
(i) 14 cm (ii) 21 cm (iii) 3.5 m

3. Find the total surface area of a hemisphere of radius 10 cm. (Use π = 3.14)

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.

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 Rs 16 per 100 cm2.

6. Find the radius of a sphere whose surface area is 154 cm2.

7. The diameter of the moon is approximately one fourth of the diameter of the earth.Find the ratio of their surface areas.

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.

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