AP EAPCET 19-Aug-2021 Shift 2 Paper

Metals emit electrons when light shines upon them. The phenomenon is called as photoelectric effect and the electrons emitted in such manner are called photoelectrons.
Relation between kinetic energy and frequency is kinetic energy =ϕ−hv
Here ϕ= metal work function

Kinetic energy of photoelectrons depends on frequency of incident light and metal work function. Cu has maximum metal work function's value.
Hence, Cu have minimum kinetic energy of ejected photoelectrons than alkali metals.