Mishonov T.M.Gourev V.N.Dimitrova I.M.Serafimov N.S.Stefanov A.A.Petkov E.G.Varonov A.M.2024-07-102024-07-102024-07-102024-07-102019-04-081361-64040143-080710.1088/1361-6404/ab07e0SCOPUS_ID:85067097643https://rlib.uctm.edu/handle/123456789/534A new experimental set-up for measurement of the Boltzmann constant is described. The statistically averaged square of voltage U2 is measured for different capacitances C. The Boltzmann constant is determined by the equipartition theorem C U2 k T = . For fixed capacitance, voltages could be measured for different temperatures. The set-up consists of low-noise, highfrequency operational amplifiers ADA4898-2. An instrumental amplifier is followed by an inverting amplifier, the square of the voltage is created by an analog multiplier AD633, and finally, the averaged signal is measured by a multimeter. More than ten high-school students were able to measure the Boltzmann constant with the experimental set-up in the 5th Experimental Physics Olympiad with excellent accuracy compared to the price, conditions and available time for the experiment. A new derivation of the important statistical physics theorems by Nyquist and Callen-Welton is given in an appendix at the level of introductory courses in physics studied by future teachers. To understand the work of the experimental set-up, it is only necessary to know the equipartition theorem.enArticle