Audible Young'S Experiment - Mic And Scope

Purpose

To demonstrate interference of sound with two coherent sound sources in a quantitative way.

Equipment

Oscillator with loudspeakers on optical rail, oscilloscope..

Setup Time

10 min.

Images

h2-24

Description

The oscillator is set to approximately 3000 Hz, with identical signals being applied to both loudspeakers.The microphone, with its signal displayed on the oscilloscope, can be moved around to observe the interference pattern by measuring the alternating maxima and minima in the intensity pattern. Nodal and antinodal lines can be observed and measurements made to show the relationships between the wavelength, source separation, and the nodal/antinodal lines.

References

Haywood Blum, Acoustic Interference Experiment, AJP 42, 413-414 (1974).