Quick Answer:The Ring and Ball Apparatus is a metal ball and ring, each on its own rod with a heat-resistant handle, sized so that the ball passes through the ring only at room temperature. Heating the ball shows that solids expand.
Last updated: 18 October 2026
Key Features
Ring is gauged so the ball just passes through at room temperature.
Ball and ring are mounted on separate rods.
Heat-resistant handles for holding over a flame.
Clear demonstration of thermal expansion of solids.
Technical Specifications
Specification
Value
Parts
Metal ball and metal ring
Mounting
Ball and ring on separate rods
Handles
Heat-resistant
Fit
Ball passes through ring at room temperature only
Principle
Volumetric thermal expansion
How It Is Used
The cold ball is first passed through the ring to show the fit. The ball is then heated in a flame and no longer goes through, because it has expanded. Once it cools, it passes through again, which links the change in size to the increased vibration of particles in a heated solid.
Frequently Asked Questions
What does the Ring and Ball Apparatus demonstrate?
Thermal expansion of solids: after heating, the ball expands and will not pass through the ring that it fits at room temperature.
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