Complete uncertainty analysis of a simple undergraduate experiment for the measurement of Planck’s constant using python

Abstract

The detailed analysis of propagation of errors in an undergraduate experiment is not dealt with utmost carefulness in general. Here an experiment is chosen from the proposed B.Sc. (Hons.) Physics syllabus submitted to the University Grant Commission, India under choice based credit system. The step by step determination of Planck’s constant and uncertainties introduced in each step are described. The least square fittings between various data sets and the evaluation of the associated uncertainties are done using python codes. Although similar experiments were studied previously, simple modification is made to improve the accuracy of the result. The major portion of the uncertainty in determining Planck’s constant arises from the least squares fitting of a particular data set containing the logarithms of the photodetector currents and the reciprocal of bulb temperatures. Another significant contribution in this regard comes from the measurement of the bulb resistance at room temperature. So a relatively high-resolution measuring instrument is used.