7227192365

Ethan Vanderbyl Lab Report2 Dr. Chen Physics234

TitlerThe Photo ElectricEffect Datę: 10/21/14 Lab Partners:Olivia,Josh Purpose:

The purpose of thislab i sto repeat the essential partofthe experiment, whichwas suggested by Einstein in 1905, and servedto establishthe quantum theory of radiation. By plotting the stopping potential as a function of the reci procaI of the wavelength of the radiation gives a straight linę plot, the slope of which can be usedtocalculate Planck*sconstant.

Historical background:

In 1905 Einsteinsuggested anexperiment that provided the first convincing experimental verification of thequantum theory. Though photo-emission of electrons from metals was observed by Hertz in 1887. Einstein conjectured that light emitted and absorbed in discrete but tiny bundles, as proposed by Planck, but itis propagated that way aswell; flying like hail of shot at the velocity of light. This conjecture explains the photo-electric effect experiment, where the velocity of the electrons leaving the surface of a metal when irradiated by monochromatic light depends upon the wavelength and not upon the intensity of the radiation. Einstein's theory was verified by precise measurements.

Diagram:

The PhotoeledricEffect Procedurę:

We beganthis experiment by initially attaininga Photoelectric Effect Apparatus, Light sources, interference filters, Workshop 750, Voltage Sensor leads, and a Laptop. After attaining the equipment we began by settingup our apparatus. First we connected all our leads into their specifiedchannels,and startedthe Data Studio program andloadedthe Photoelectric Effect experiment. Next we attained a light source and then attached the first fil ter to it. Next we turned the "Voltage Adjust" knob to a voltage high enough to stop the current, and we adjusted