If φ is the work function of photosensitive material in eV and light of wavelength of numerical value λ=(h c)/e metre, is incident on it with energy…

If $\displaystyle \phi$ is the work function of photosensitive material in eV and light of wavelength of numerical value $\displaystyle \lambda=\frac{h c}{e}$ metre, is incident on it with energy above its threshold value at an instant then the maximum kinetic energy of the photo-electron ejected by it at that instant (Take $\displaystyle h$-Planck's constant, $\displaystyle c$-velocity of light in free space) is (in SI units):