Last updated at May 29, 2018 by Teachoo

Transcript

Ex 13.1, 4 A cubical block of side 7 cm is surmounted by a hemisphere. What is the greatest diameter the hemisphere can have? Find the surface area of the solid. The hemisphere can occupy whole of the side of cube. Hence, Greatest diameter of hemisphere = side of cube = 7 cm Here, base of hemisphere falls on cube, so that Area should not from part of solid. Surface area of solid = Area of cube + Curved surface area of hemisphere Base area of hemisphere Area of cube Here, a = side = 7 cm Area of cube = 6a2 = 6 (7)2 = 6 (7 7) = 6 49 = 294 cm2 Curved surface area of hemisphere Diameter of hemisphere = 7 cm Hence, radius = r = (Diameter )/2 = 7/2 cm Curved Surface area of hemisphere = 2 2 = 2 22/7 (7/2)^2 = 2 22/7 7/2 7/2 = 77 cm2 Base area of hemisphere Base of hemisphere is a circle with radius = radius of hemisphere = r = 7/2 Base area of hemisphere = r2 = 22/7 (7/2)^2 = 22/7 7/2 7/2 = 77/2 cm2 Now, Surface area of solid = Area of cube + Curved surface area of hemisphere Base area of hemisphere = 294 + 77 77/2 = 294 + 77 38.5 = 371 38.5 = 332.5 cm2 Hence, Surface area of solid = 332.5 cm2

Example 2
Important

Example 3 Important

Ex 13.1, 4 Important You are here

Ex 13.1, 9 Important

Example 6 Important

Example 7 Important

Example 9 Important

Example 11 Important

Ex 13.3, 8 Important

Ex 13.3, 9 Important

Example 12 Important

Ex 13.4, 4 Important

Ex 13.4, 5 Important

Surface Area and Volume Formulas Important

Class 10

Important Questions for Exam - Class 10

- Chapter 1 Class 10 Real Numbers
- Chapter 2 Class 10 Polynomials
- Chapter 3 Class 10 Pair of Linear Equations in Two Variables
- Chapter 4 Class 10 Quadratic Equations
- Chapter 5 Class 10 Arithmetic Progressions
- Chapter 6 Class 10 Triangles
- Chapter 7 Class 10 Coordinate Geometry
- Chapter 8 Class 10 Introduction to Trignometry
- Chapter 9 Class 10 Some Applications of Trignometry
- Chapter 10 Class 10 Circles
- Chapter 11 Class 10 Constructions
- Chapter 12 Class 10 Areas related to Circles
- Chapter 13 Class 10 Surface Areas and Volumes
- Chapter 14 Class 10 Statistics
- Chapter 15 Class 10 Probability

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.