In photoelectric emission,`1/2mv^2=hv-phi_0`.
The increase in frequency v of incident light increase the energy of the incident photon.since the work function `phi_0` of a given photosenstive surface being fixed, therefore the kinetic energy of the photoelectron increases with increase in the photoelectron increase with increase in the frequency of incident light due to it, the velocity v of photoelectrons increase.
