Experiment Description

Experiment

Experiment C05    Newton's Rings

Objectives
  • Study Newton's Rings using school laboratory apparatus
  • Estimate radius of curvature from radii of Newton's Rings
  • Estimate the refractive index of water through the change in Newton's Rings
Description
In this activity, you will use a sodium lamp and a travelling microscope to study the Newton's Rings which are explained by the interference of light. A convex lens is placed on a clean glass block. Light reflected by the lower surface of the lens and the upper surface of the glass block would interfere to form Newton's Rings.

In Experiment 1, you will locate the Newton's Rings directly without the travelling microscope and then measure the radii of the rings by the travelling microscope.

Experiment 2 is similar to Experiment 1 except that a thin layer of water replaces the air gap.
Apparatus
sodium lamp [1]
convex lens focal length 100 cm [1]
convex lens focal length 30 cm [1]
glass block [1]
travelling microscope [1]
single floppy disk plastic box [1]
stand-and-clamp [1]
protractor [1]
methylated sprite [1]
lens cleaning cloth [1]
eye-dropper [1]
beaker of water [1]
ray box [1]
Experiment