AIM

To find the velocity of sound waves in a given rod with Kundt's tube apparatus

For showing the wavelength of vibrations in air in a closed tube, by  the  depositing of lycopodium or fine cork dust at the nodes. 

THEORY

Kundt's tube is an acoustical apparatus, invented by German Physicist, August Kundt (1866). Knowing the speed of sound in air, the speed of sound V in a solid rod can be calculated based on the measurement of sound wavelength, λ. If the frequency of the sound wave, f is known, we can calculate the speed of sound as,V =fv

CONVENTIONAL MODEL 

Comprising a glass tube approximately 100 cm. in length and 35 mm diameter, provided at one end with a tightly fitting but adjustable cork piston on a ALUMINUM rod 390 mm long, and at the other end with  a loose fitting piston attached to a ALUMINUM sounding rod.

The Glass Tube is fitted on a Laminated Board( plank) 1.2 meter long with two wooden brackets & the piston moves  inside the Glass tube. 

The Lycopodium powder is spread inside and the piston is swiftly pulled from one side.  It is said to give waves inside the Glass tube (which is very difficult to observe or to do in this method).