Answer:
Work function will be 2.8125 eV
Explanation:
We have given maximum wavelength that electromagnetic wave emit [tex]\lambda =440nm=440\times 10^{-9}m[/tex]
Plank's constant [tex]h=6.6\times 10^{-34}Js[/tex]
Speed of light [tex]c=3\times 10^8m/sec[/tex]
Work function is equal to [tex]W=\frac{hc}{\lambda }=\frac{6.6\times 10^{-34}\times 3\times 10^8}{440\times 10^{-9}}=4.5\times 10^{-19}j[/tex]
We know that [tex]1ev=1.6\times 10^{-19}j[/tex]
So [tex]4.5\times 10^{-19}j=2.8125eV[/tex]
