Question

lf the work function of a metal is 6.63 × 10–19 J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ______ nm. (Nearest integer)
[Given : h = 6.63 × 10–34 J s, and c = 3 × 108 m s–1]

Answer 1

∵ $E =\frac {hc}{λ}$
$6.63×10^{-19} =\frac {6.63×10^{-34}×3×10^8}{λ}$
$λ=3×10^{-7}$ m
$λ= 300×10^{-9}$ m
$λ= 300$ nm

So, the answer is $300$.