A student performs an experiment to observe photoelectric effect by shining light on a metal surface. The light source limits light of wavelength 450nm. The table given below lists the available metals and their corresponding work functions
Metalϕ(ev)Tungsten4.5Lithium2.3Barium2.5Tantalum4.2
Suppose the photoelectric experiment is done separately with these metals with light of wavelength 450nm. The maximum magnitude of stopping potential amongst all the metals is
0.45 V
Kmax=eV0
⇒V0=Kmaxe=Eincident−ϕe=(2.75−2.3e)=0.45V