Experimental investigation of the randomness of the coherer effect in granular conducting materials

Wepresent an educational activity concerning the experimental investigation of the randomness of the coherer effect observed in granular conducting materials. For this purpose, we built different coherers that allowed us to easily measure their electric resistance. The dispersion of the experimental data have been characterized by calculating the mean, standard deviation, and relative standard deviation of the measured values. The histograms have been compared with the corresponding Gaussian distribution function. The proposed experimental activity can be easily carried out in classroom, at secondary and high school physics laboratory. It gives the opportunity to teach/learn concepts concerning topics of electromagnetic wave transmission and detection at an elementary level and also to contribute to increase student’s engagements in physics.