Question

The photoelectric work function for a metal is 4.2 eV. If the stopping
potential is 3 V, find the threshold wavelength and the maximum kinetic
energy of emitted electron.​

Answer 1

Answer:

Data: e=1.6×10−19C,c=3×108m/s,h=6.63×10−34J.s,Φ=4.2eV=4.2×1.6×10−19J=6.72×10−19J,Vs=3V

The threshold wavelength,

λ0=hcΦ

=(6.63×10−34)(3×108)6.72×10−19

=19.896.72×10−7=2.960×10−7m=2960Å

The maximum kinetic energy of emitted electrons, KEmax

=eVs=(1.6×10−19)(3)=4.8×10−19 J

Explanation:

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Answer 2

Explanation:

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