012-04049J
h/e Apparatus and h/e Apparatus Accessory Kit
11
®
According to the quantum model of light, the energy of light is directly proportional to its
frequency. Thus, the higher the frequency, the more energy it has. With careful experimentation,
the constant of proportionality, Planck's constant, can be determined.
In this lab you will select different spectral lines from mercury and investigate the maximum en-
ergy of the photoelectrons as a function of the wavelength and frequency of the light.
Setup
Set up the equipment as shown in the diagram below. Focus the light from the Mercury Vapor
Light Source onto the slot in the white reflective mask on the h/e Apparatus. Tilt the Light Shield
of the Apparatus out of the way to reveal the white photodiode mask inside the Apparatus. Slide
the Lens/Grating assembly forward and back on its support rods until you achieve the sharpest im-
age of the aperture centered on the hole in the photodiode mask. Secure the Lens/Grating by tight-
ening the thumbscrew.
Align the system by rotating the h/e Apparatus on its support base so that the same color light that
falls on the opening of the light screen falls on the window in the photodiode mask with no overlap
of color from other spectral bands. Return the Light Shield to its closed position.
Check the polarity of the leads from your digital voltmeter (DVM), and connect them to the OUT-
PUT terminals of the same polarity on the h/e Apparatus.
Experiment 2: The Relationship between Energy,
Wavelength, and Frequency
Experiment 2. Equipment Setup
Содержание h/e Apparatus
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