Thaned Pruttivarasin, Narumon Emarat and Kwan Arayathanitkul
Rationale and objective: Physics laboratories often demonstrate simple mathematical relationships — current proportional to voltage (Ohm's law), or distance proportional to time squared in motion. Relationships where one quantity depends on another raised to a very high power are far rarer in lab settings, yet they offer valuable opportunities to teach advanced data analysis beyond straight-line fitting.
Summary: This study investigates whether a common, low-cost electronic component — a 3.6 V Zener diode — can serve as a clean classroom demonstration of such a high-order relationship. When connected in reverse (reverse bias), the diode's current-voltage behaviour was measured using only batteries, standard resistors, and a digital multimeter.
Outcome: The results show that the current through the diode follows the voltage raised to the 8th power (I ∝ V8), confirmed across approximately ten diodes of the same model. Plotting the data on a log-log scale produces a remarkably straight line, making the power-law relationship visually obvious and easy to analyse.
Acknowledgement: Department of Physics, Faculty of Science, Mahidol University
Related SDGs goal: 4. Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all
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Fisher D G (1992) Diode characteristics to determine Boltzmann constant. Phys. Teach. 30 315-6.
Önder F, Önder E B and Ogur M (2019) Determination of diode characteristics by using Arduino.
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