{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

28.1 Physics 6C Photoelectric Effect

28.1 Physics 6C Photoelectric Effect - Physics6C...

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

View Full Document Right Arrow Icon
Physics 6C The Photoelectric Effect Prepared by Vince Zaccone For Campus Learning Assistance  Services at UCSB
Image of page 1

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

View Full Document Right Arrow Icon
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.
Image of page 2
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
Image of page 3

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

View Full Document Right Arrow Icon
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.
Image of page 4
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 λ = = c h f h E photon φ - = hf K max Φ , 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.
Image of page 5

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

View Full Document Right Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern