PHYSICS 244 . 
EXPERIMENT #1
 

Q.1.     What is a photon?  How much energy does an electron receive
when it absorbs a photon of frequency ν ? 

 

Q.2.     If the electron from Q.1 must use an amount of energy equal
to φ, the work function of the phototube cathode, in order to escape
the cathode's surface, how much kinetic energy does it have once it
escapes?  

 

Q.3.     What is the energy required for an electron of charge -e to
travel across a potentital difference of -V?  

 

Q.4.     If there are two frequencies of light, with ν1 > ν2 > 0, in a
light beam shining on a phototube whose work function is f0 at what
level of applied voltage across the phototube will all the electrons
which received a photon of frequency ν2 be stopped?  Which received a
photon of frequency ν1?  Which of these voltages is greater?  

 

Q.5.     Use the charts given on page 6. For the orange filter, which
of the two spectral lines should determine the extinction voltage for
the phototube? For the blue filter?

 


Lab writeup