Ultraviolet light is incident on two photosensitive materials having work functions `W_(1)` and `W_(2)(W_(1) gt W_(2))`. In which case will the kinetic energy of the emitted electrons be greater ? Why ?

Explanation

From Einstein's photoelectric equation `hv = W + Ek`
`E_(k) = hv-W`
Clearly, smaller the work function, greater is the K.E.As `W_(1) gt W_(2) `, K.E. for metal of work function `W_(2)` will be greater.