The PC‑101 experimental setup is designed for the precise determination of Planck’s constant (h) using the photoelectric effect—a fundamental principle of quantum mechanics. This classic experiment enables students and researchers to verify the quantized nature of light by observing the linear relationship between the stopping potential and the frequency of incident light.

The apparatus includes a photoelectric tube, precision voltmeter, variable intensity light sources (LEDs or filtered lamps) of known wavelengths, and a calibrated measuring unit. The setup allows easy measurement of cut-off voltages corresponding to different wavelengths, from which Planck’s constant can be calculated with high accuracy.

This compact and robust system is ideal for use in undergraduate physics laboratories, enabling practical validation of the photoelectric equation:
eV₀ = hf − ϕ

Key Features

• Accurate determination of Planck’s constant (h)

• Uses photoelectric tube and known monochromatic light sources

• Built-in variable voltage supply and voltmeter

• Fast response and stable readings

• Clear and reproducible linear plot of stopping potential vs frequency

• Comes with calibrated filters, manual, and pre-mounted components

• Compact, durable, and easy to operate

Applications

• Experimental proof of the quantum nature of light

• Measurement of Planck’s constant and work function

• Study of the photoelectric effect and threshold frequency

• Ideal for B.Sc., M.Sc., and engineering physics laboratories

• Foundation for understanding photon energy, quantum mechanics, and photoemission