Work function of nickel is 5.01 eV. When ultraviolet radiation of wavelength 200 Ao is incident on it, electrons are emitted. What will be the maximum velocity of emitted electrons?

Energy corresponding to 2000Å=12375/2000eV=6.2eVE=W+KEMaximum kinetic energy is(6.2−5.01)eV=1.19eV Now,  12×9.1×10−31×vmax2=1.19×1.6×10−19 or  vmax2=1.19×1.6×10−19×29.1×10−31 =0.418×1012=41.8×1010 or vmax=6.46×105ms−1