Demonstrations

Photoelectric Effect Stopping Potential

Code Number :	7A10.32
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Good
Principle :	Photoelectric Effect
Area of Study :	Modern Physics
Equipment :	Variac, voltmeter, 40 watt light bulb or mercury vapor lamp, Pasco photoelectric head, colored filters, neutral density filter.
Procedure :	Connect the photoelectric head to the voltmeter and place the light bulb a few inches in front of the head input slit. Turn on the light bulb to a desired intensity and observe the stopping voltage. Insert the filters and again observe the stopping voltage for each filter. The stopping voltage should be higher toward the blue end of the spectrum. The neutral density filter may be used to show that the stopping voltage does not depend upon intensity.

References

Adolf Cortel, "Tweaking 'Simple Photoelectric Effect' Demo", TPT, Vol. 44, # 7, Oct. 2006, p. 406.

Adolf Cortel, "Simple Photoelectric Effect", TPT, Vol. 44, # 5, May 2006, p. 310.

Howard Fisher, "Planck's Constant Experiment", TPT, Vol. 23, # 6, Sept. 1985, p. 334.

Evan S. Snyder, "A Correction to the Pholoelectric Current in the Planck's Constant Experiment", TPT, Vol. 23, # 2, Feb. 1985, p. 98 - 99.

Dr. Hanna Goldring, "Correction Corrected", TPT, Vol. 17, #7, Oct. 1979, p. 416.

Herbert H. Gottlieb, "Photoelectric Effect Using a Transistorized Electrometer", TPT, Vol. 3, # 8, Nov. 1965, p. 380.

J. Dean Barnett, Harold T. Stokes, "Improved Student Laboratory on the Measurement of Planck's Constant using the Photoelectric Effect," AJP, Vol. 56, # 1, Jan. 1988, p. 86.

R. A. Powell, "Photoelectric Effect: Back to Basics", AJP, Vol. 46, # 10, Oct. 1978, p. 1046.

Thomas R. Carver, John O. Crawford, "Useful Lecture Demonstration of Photoelectric Wavelength Threshold", AJP, Vol. 43, # 4, Apr. 1975, p. 370.

MPb-1: Freier and Anderson, A Demonstration Handbook for Physics.

T. D. Rossing, C. J. Chiaverina, "2.9, The Particle Nature of Light: Observing Photons", Light Science, Physics and Visual Arts, p. 34.

Mail Questions and Comments to: Dale Stille