Pre-Lab questions for Lab 1
1.  A central theme of PHY 293 - Contemporary Physics Laboratory -  is the wave-particle duality.  In the photoelectric effect, Einstien showed (and received the Nobel Prize for his efforts) that light behaves as if it were a particle.

a) Discuss how the results of the photoelectric effect experiment would differ if light behaved purely as a wave.  (as always, feel free to consult reference books at your disposal).

b) When did Einstein receive the nobel prize for this work?

2. In Lab0 you learned how to perform a least-squares fit to a linear equation.  In Lab1 you will perform a least square fit to a linear equation that has physical significance:

V = (h/e)f - (work function of the electrode/e)
which is identical in form to the more familiar,
y = mx + b.
The quantities of interest in this experiment are Planck's constant and the work function of the electrode material.  Your measurements will be simply the stopping potential for photoelectrons as a function of the frequency of the input light to the photocell.

a) You will be supplied with the wavelengths of the input light.  How will you determine the corresponding frequencies?

b) Dimensionally, the relation of interest is a potential difference (a voltage).  How will your best fit analysis of your results provide you with a value (in eV) for the work function of the electrode?  Please be specific.   (how does one convert volts to eV???)

3.  The light input to the various photocells in this experiment will be provided by ac mercury discharge lamps (the overhead lights are also ac Hg-discharge lamps - i.e.. fluorescent lamps.).  Should we turn the overhead lights off in the lab room when we perform this experiment?    Why or why not?

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