1.
The work function of a certain metal is 3.31×10−193.31 \times 10^{-19} J. Then, the maximum kinetic energy of photoelectrons emitted by incident radiation of wavelength 50005000 \AA is (Given, h=6.62×10−34h = 6.62 \times 10^{-34} Js, c=3×108c = 3 \times 10^8 ms−1^{-1}, e=1.6×10−19e = 1.6 \times 10^{-19} C)