lab5_photoelectric_effect

lab5_photoelectric_effect - PHY 252 Lab 5: the...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
PHY 252 Lab 5: the Photoelectric Effect Fall 2009 In this experiment you will use the photoelectric effect to measure the Planck constant h . While measurements of the Planck blackbody spectrum led to earlier measurements of h , precision mea- surements based on the photoelectric effect led to the first precise determination of h , and in 1926 R. A. Millikan received the Nobel Prize for these measurements. A phototube is illuminated by light of a known wavelength. Electrons are ejected from the photocathode with some kinetic energy E k . They are collected as anode current unless a variable retarding potential V stop is large enough to stop the electrons (at which point we refer to that voltage as the “stopping potential”). At this stopping potential V stop , all electrons with charge e , and thus kinetic energy E k = e · V , will be stopped, which can be described with E k = hc λ - φ = e · V stop , (1) where λ = c/ν is the wavelength of the incident light and φ is a work function of the cathode
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/28/2011 for the course PHY 251 taught by Professor Rijssenbeek during the Fall '01 term at SUNY Stony Brook.

Page1 / 2

lab5_photoelectric_effect - PHY 252 Lab 5: the...

This preview shows document pages 1 - 2. Sign up to view the full document.

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