NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 12: Surface Areas & Volumes - Exercise 12.1Question 3
Class 10 - Mathematics - CHAPTER 12: Surface Areas & Volumes - Exercise 12.1
Question. 3
A plumbline (sahul) is the combination of (see Fig.)
(A)
a cone and a cylinder
(B)
a hemisphere and a cone
(C)
frustum of a cone and a cylinder
(D)
a sphere and a cylinder
Detailed Answer with Explanation:
Step 1: Look carefully at the figure of the plumbline (sahul).
Step 2: The lower portion of the plumbline is pointed, like an ice-cream cone. This shape is called a cone.
Step 3: The upper portion is not flat. Instead, it is smoothly rounded, like half of a ball. This shape is called a hemisphere.
Step 4: So, the plumbline is made up of two solid shapes joined together — a cone at the bottom and a hemisphere at the top.
Final Answer: A plumbline is a combination of a hemisphere and a cone.