Identification of planck’s constant by Light Emitting Diodes (LEDS) / Nurain Azmi ... [et al.]

Azmi, Nurain and Mustafa, Sabirin and Mohd Yunos, Nur Hazirah and Wan Mohd Sakri, Wan Nor Azlin and Abdul Halim, Muhammad Nazzim and Aadenan, Amin (2020) Identification of planck’s constant by Light Emitting Diodes (LEDS) / Nurain Azmi ... [et al.]. Journal of Academia, 8. pp. 33-38. ISSN 2289-6368


In this paper, a simple analysis yet a straight forward method of determining the Planck’s constant by evaluating the stopping potential of five different colors of light emitting diodes (LEDs) is presented. The study aimed to identify the Planck’s constant based on the relationship between the potential difference of LEDs to their respective frequencies under room temperature with low illumination of ambient light by applying a simple theoretical analysis. The experiment was performed by connecting the circuit in series connection and the voltage reading of LEDs were recorded and then presented in a graph of frequency, f versus stopping voltage, Vo. To determine the Planck’s constant, the best fit line
was analyzed and the centroid was also identified in order to find the minimum and maximum errors due the gradient of the graph. From the analysis, results showed that the Planck constant value was (5.997 ± 1.520) × 10–34 J.s with approximately 10% of deviation from the actual value. This
demonstrates that a simple analysis can be utilized to determine the Planck’s constant for the purpose of the laboratory teaching and learning at the undergraduate level and can be served as a starting point for the students to understand the concept of quantization of energy in Modern Physics more effectively. This is to further suggest that the Planck’s constant can be identified via a low-cost and unsophisticated experimental setup.


Item Type: Article
Email / ID Num.
Azmi, Nurain
Mustafa, Sabirin
Mohd Yunos, Nur Hazirah
Wan Mohd Sakri, Wan Nor Azlin
Abdul Halim, Muhammad Nazzim
Aadenan, Amin
Subjects: Q Science > Q Science (General) > Study and teaching
Q Science > Q Science (General) > Study and teaching > Laboratories. General works
Q Science > QC Physics
Divisions: Universiti Teknologi MARA, Negeri Sembilan
Journal or Publication Title: Journal of Academia
UiTM Journal Collections: UiTM Journal > Journal of Academia (JoA)
ISSN: 2289-6368
Volume: 8
Page Range: pp. 33-38
Keywords: Planck’s constant, LEDs, Modern Physics, Undergraduate’s laboratory
Date: 2020
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