EuPhO 2026, experiment — Задача 2. Task E2: Acoustic levitator properties (4.0 pts)

Experimental task Language: English · 4 т.

Условие

In what follows, to levitate a small solid object, the voltage of the connected power supply can be initially put to a high voltage, for example 17 V. The object can be placed in the nodes by using the tweezers. Note that the levitating object can oscillate horizontally due to air-turbulence; wait a little for things to settle. Small oscillations are not detrimental to measurement results.

Remember to return the Mode X switch to position O for the rest of the exam.

a) Design, sketch and use a setup to determine as precisely as possible the frequency of the transducers. The speed of sound in air is $v \approx 340\ \mathrm{m/s}$. [2 т.]

b) Switch Mode X to position I on the electrical box (F) to change to a different mode of operation where the transducers in the upper half of the levitator are supplied with a slightly different frequency $(f + \Delta f)$ than the lower one. Describe the changed behaviour of the levitated objects in this mode and determine the frequency difference $\Delta f$ and its sign. [2 т.]

Решение

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Оригинал в Архива: eupho2026_experiment_problems.pdf · официални решения: eupho2026_experiment_solutions.pdf