Volume of Sphere MCQs Quiz | Class 9

This Class IX Mathematics (Code 041) quiz covers Unit V: Mensuration, specifically focusing on the Volume of Sphere. Topics include the volume formula, calculations involving radius and diameter, and real-life applications. Test your understanding, view your score immediately, and click “Download Answer PDF” to save your results for offline revision.

Overview of Sphere Mensuration

In Class 9 Mathematics, Mensuration involves studying geometric shapes and their parameters like volume and surface area. The sphere is a perfectly round 3D object where every point on the surface is equidistant from the center. Understanding the volume of a sphere is crucial for solving problems related to capacity, displacement, and material requirements.

Key Formulas

The primary formula for the volume of a sphere depends on its radius (r). If the diameter (d) is given, remember that radius is half of the diameter (r = d/2).

Shape Parameter Formula
Sphere Volume (4/3) x pi x r^3
Hemisphere Volume (2/3) x pi x r^3

Common Applications

  • Recasting: Melting a large metal sphere to form smaller spheres. The total volume remains constant.
  • Displacement: Calculating the rise in water level when a spherical object is submerged.
  • Capacity: Finding how much liquid a hemispherical bowl can hold.

Quick Revision Points

  • Unit Consistency: Always ensure radius and volume are in consistent units (e.g., cm and cubic cm).
  • Value of Pi: Use 22/7 or 3.14 as specified. If not specified, 22/7 is standard.
  • Cubic Units: Volume is always measured in cubic units (cm^3, m^3).

Extra Practice Questions

1. A sphere has a radius of 7 cm. Find its volume using pi = 22/7.
2. How many lead shots of radius 1 cm can be made from a sphere of radius 4 cm?
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 cm cube?
4. Find the volume of a hemisphere of radius 3.5 cm.
5. If the volume of a sphere is numerically equal to its surface area, what is its radius?