Class 9, Maths, Chapter 13, Exercise 13.8, Solutions
Q.1. Find the volume of a sphere whose radius is
(i) 7 cm
(ii) 0.63 m
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Q.2. Find the amount of water displaced by a solid spherical ball of diameter
(i) 28 cm
(ii) 0.21 m
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Q.3. The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8.9 g per cm3?
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Q.4. The diameter of the moon is approximately one-fourth of the diameter of the earth. What fraction of the volume of the earth is the volume of the moon?
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Q.5. How many litres of milk can a hemispherical bowl of diameter 10.5 cm hold?
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Q.6. A hemispherical tank is made up of an iron sheet 1 cm thick. If the inner radius is 1 m, then find the volume of the iron used to make the tank.
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Q.7. Find the volume of a sphere whose surface area is 154 cm2.
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Q.8. A dome of a building is in the form of a hemisphere. From inside, it was white-washed at the cost of ₹4989.60. If the cost of white-washing is ₹20 per square metre, find the
(i) inside surface area of the dome,
(ii) volume of the air inside the dome.
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Q.9. Twenty-seven solid iron spheres, each of radius r and surface area S are melted to form a sphere with surface area S′. Find the
(i) Radius r′ of the new sphere,
(ii) Ratio of S and S′.
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Q.10. A capsule of medicine is in the shape of a sphere of diameter 3.5 mm. How much medicine (in mm3) is needed to fill this capsule?
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NCERT Solutions For Class 9 Maths Chapter 13, Surface Area And Volume (All Exercises)
- Class 9, Maths, Chapter 13, Exercise 13.1
- Class 9, Maths, Chapter 13, Exercise 13.2
- Class 9, Maths, Chapter 13, Exercise 13.3
- Class 9, Maths, Chapter 13, Exercise 13.4
- Class 9, Maths, Chapter 13, Exercise 13.5
- Class 9, Maths, Chapter 13, Exercise 13.6
- Class 9, Maths, Chapter 13, Exercise 13.7
- Class 9, Maths, Chapter 13, Exercise 13.8