Q.
A light whose frequency is equal to 6×1014Hz is incident on a metal whose work function is 2eV.[h=6.63×10−34Js,1eV=1.6×10−19J]
The maximum energy of the electrons emitted will be
KEmax=hv−ϕ
where hv= energy of incident photon, ϕ= work function KEmax=6.6×10−34×6×1014−2×1.6×10−19 =3.96×10−19−3.2×10−19 =1.6×10−190.76×10−19eV =0.475eV