In this chapter, we provide RD Sharma Solutions for Chapter 21 Surface Areas and Volume of a Sphere VSAQS for English medium students, Which will very helpful for every student in their exams. Students can download the latest RD Sharma Solutions for Chapter 21 Surface Areas and Volume of a Sphere VSAQS Maths pdf, free RD Sharma Solutions for Chapter 21 Surface Areas and Volume of a Sphere VSAQS Maths book pdf download. Now you will get step by step solution to each question.

Textbook | NCERT |

Class | Class 9 |

Subject | Maths |

Chapter | Chapter 21 |

Chapter Name | Surface Area and volume of A Sphere |

Exercise | VSAQS |

**RD Sharma Solutions for Class 9 Chapter 21 Surface Areas and Volume of a Sphere VSAQS**

Question 1.

Find the surface area of a sphere of radius 14 cm.

Solution:

Radius of a sphere (r) = 14 cm

∴ Surface area = 4πr^{2} = 4 x 227 x 14 x 14 cm^{2}

= 2464 cm^{3}

Question 2.

Find the total surface afea of a hemisphere of radius 10 cm.

Solution:

Radius of hemisphere (r) = 10 cm

∴ Total surface area = 3πr^{2}

Question 3.

Find the radius of a sphere whose surface area is 154 cm^{2}.

Solution:

Surface area of a sphere = 154 cm^{2}

Question 4.

The hollow sphere, in which the circus motor cyclist performs his stunts, has a diameter of 7 m. Find the area available to the motor cyclist for riding.

Solution:

Diameter of hollow sphere = 7 m

Question 5.

Find the volume of a sphere whose surface area is 154 cm^{2}.

Solution:

Surface area of a sphere = 154 cm^{2}

Question 6.

How many spherical bullets can be made out of a solid cube of lead whose edge measures 44 cm, each bullet being 4 cm in diameter?

Solution:

Edge of a solid cube = 44 cm

∴ Volume = a^{2} = (44)^{2} cm^{2}

= 44 × 44 × 44 cm^{3}

Diameter of a spherical bullet = 4 cm

Question 7.

If a sphere of radius 2r has the same volume as that of a cone with circular base of radius r, then find the height of the cone.

Solution:

Radius of a sphere (R) = 2r

Question 8.

If a hollow sphere of intefnal and external diameters 4 cm and 8 cm respectively melted into a cone of base diameter 8 cm, then find the height of the cone.

Solution:

Internal diameter of a hollow sphere = 4cm

∴ Internal radius = 42 = 2 cm

Similarly the outer radius (R) = 82 = 4 cm

∴ Volume of melted used in hollow sphere

Question 9.

The surface area of a sphere of radius 5 cm is five times the area of the curved surface of a cone of radius 4 cm. Find the height of the cone.

Solution:

Radius of a sphere (r) = 5 cm

∴ Surface area = 4πr^{2}

= 4π x 5 x 5 = 100π cm^{2}

Radius of cone (r_{1}) = 4 cm

Question 10.

If a sphere is inscribed in a cube, find the ratio of the volume of cube to the volume of the sphere.

Solution:

Let edge of a cube = a

Then its volume = a^{3}

∵ A sphere is inscribed in the cube

∴ Diameter of sphere = a

**All Chapter RD Sharma Solutions For Class 9 Maths**

—————————————————————————–**All Subject NCERT Exemplar Problems Solutions For Class 9**

**All Subject NCERT Solutions For Class 9**

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