Higher Physics Lab Waves & Sound



Exp-1 To study acoustic cavity resonators and determine their characteristic frequency.
Exp-2 To study the dependence of characteristic frequency on the volume of cavity of the resonator.

  • Easy setup.
  • Quick measurement.
  • Computer based data collection.
  • FFT analysis.
  • Cavity resonator.
  • Resonance frequency.
  • Acoustic resonant circuit.
  • Undamped oscillation.
  • Fast Fourier transformation.

Principle and Working:
Helmholtz resonator is described by a cavity of air with an opening which resonates at a natural frequency when the air is excited. The relationship of the resonate frequency to the volume of the cavity and size of the port is given by the following equation.

where f is the frequency of resonance, ν the velocity of sound in air, A the cross-sectional area of the port, V0 the static volume of the cavity, and Le the effective length of the port, which is L+1.5r, where L is the actual length and r the port radius (circular port). The resonance frequency varies linearly with the inverse square root of volume which can be investigated in the present setup.


Cat. No. Item Name Qty.
  Data Logging Interface 1
  Sound sensor 1
SC337 Round bottom flask 1
SC335 Round bottom flask 1
SH310 Support base 1
SH323 Support rod 1
SW092 Boss head 2
SV190 Three finger clamp 2
SF667 Measuring cylinder 1
R5023 Vernier Caliper 1
SP139 Ruler 1

* Additionally Required
Computer not supplied with this setup.

Waves & Sound Experiments