Experimental set-up for Boltzmann constant determination by equipartition theorem for capacitors

Abstract

A new experimental set-up for Boltzmann constant measurement is described. Statistically averaged square of voltage 〈U2〉 is measured for different capacitances C and the Boltzmann constant is determined by the equipartition theorem C 〈U2〉 = kB T. The set-up consists of low-noise high frequency operational amplifiers ADA4898-2. An instrumental amplifier is followed by an inverting amplifier, square of the voltage is created by an analog multiplier AD633 and finally the averaged signal is measured by a multimeter. More than 10 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. For the understanding of the work of the experimental set-up, it is necessary to know only the equipartition theorem.