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howin
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[SOLVED] Photoelectric effect, retarding potential
If the photocurrent of a photocell is cut off by a retarding potential of 0.92 volts for monochromatic radiation of 2500 A (A with the little circle above it), what is the work function of the material.
My book and professor use different symbols so I am going to define the symbols I am using:
Ø means retarding potential / stopping potential
W means work function
e Ø = hc/lambda - W
hc = 1240 eV
radiance is invariant with lambda b/c monochromatic
According to the graph of photocurrent i vs. anode voltage V, it is when V = -Ø that i goes to 0. I don't see where 2500A fits in, except that that must give me lambda so that I can solve for W in the equation above.
Homework Statement
If the photocurrent of a photocell is cut off by a retarding potential of 0.92 volts for monochromatic radiation of 2500 A (A with the little circle above it), what is the work function of the material.
Homework Equations
My book and professor use different symbols so I am going to define the symbols I am using:
Ø means retarding potential / stopping potential
W means work function
e Ø = hc/lambda - W
hc = 1240 eV
The Attempt at a Solution
radiance is invariant with lambda b/c monochromatic
According to the graph of photocurrent i vs. anode voltage V, it is when V = -Ø that i goes to 0. I don't see where 2500A fits in, except that that must give me lambda so that I can solve for W in the equation above.