28.1 Physics 6C Photoelectric Effect

28.1 Physics 6C Photoelectric Effect - Physics 6C The...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Physics 6C The Photoelectric Effect Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB incoming light e- e- e- e- e- e- e- e- metal plate Photoelectric Effect Here is the basic setup for the experiment. Light shines on the metal plate, and the electrons absorb that light energy. Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB e- e- e- e- e- e- e- e- metal plate Photoelectric Effect Here is the basic setup for the experiment. Light shines on the metal plate, and the electrons absorb that light energy. Sometimes the electrons gain enough energy to escape and they are ejected from the metal plate, creating a current in the circuit. Surprisingly, whether or not the electrons are freed does not depend on the brightness of the light. Instead, it depends on the FREQUENCY of the incoming light. ejected electron Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB e- e- e- e- e- e- e- e- metal plate Photoelectric Effect ejected electron This result is not easily explained with the wave theory of light. Instead, if we think of light as photons it makes some sense. Each photon of light has an energy (proportional to its frequency), and the electrons can only interact with one photon at a time. This is why the electrons are not ejected by frequencies that are too low, even when the light is very bright. As soon as the frequency of the photon is above some threshold, the electrons can get ejected, with any leftover energy going toward their kinetic energy. Here is the basic setup for the experiment. Light shines on the metal plate, and the electrons absorb that light energy. Sometimes the electrons gain enough energy to escape and they are ejected from the metal plate, creating a current in the circuit. Surprisingly, whether or not the electrons are freed does not depend on the brightness of the light. Instead, it depends on the FREQUENCY of the incoming light. Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB e- e- e- e- e- e- e- e- metal plate Photoelectric Effect Here are the relevant formulas: Energy of a photon : ejected electron = = c h f h E photon - = hf K max , the work function of the metal, tells you how much energy is required to free the electron. Think of it as a binding energy if you like. Each metal has a different value for work function....
View Full Document

This note was uploaded on 09/09/2011 for the course PHYSICS 6c taught by Professor Staff during the Spring '11 term at UCSB.

Page1 / 32

28.1 Physics 6C Photoelectric Effect - Physics 6C The...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online