The photoelectric thresshold wavelength of silver is 3250×10−10 m. The velocity of the electron ejected from a silver surface by ultraviolet light of wavelength 2536×10−10 m is approximately
(Given h=4.14×10−15 eV and c=3×108 ms−1)
Kinetic Energy, 12mv2=hc[1λ−1λ0]
Also we can write in terms of frequency,
12mv2=hv−hvo
hv=4.14×10−15×3×1032536×10−10=4.897 eV
hv0=4.14×10−15×3×1033250×10−10=3.32 eV
12mv2=4.897−3.32=1.077 eV
v=√2×1.077×1.6×10−199.1×10−31
v=0.615×106 m/s