Question # Ejection of the photoelectron from metal in the photoelectric effect experiment can by stopped by applying ( 0.5 mathrm{V} ) when the radiation of ( 250 mathrm{nm} ) is used. The work function of the metal is:

# Ejection of the photoelectron from metal in the photoelectric effect experiment can by stopped by applying ( 0.5 mathrm{V} ) when the radiation of ( 250 mathrm{nm} ) is used. The work function of the metal is:

(1) 4 ev

( begin{array}{ll}text { (2) } 5.5 mathrm{eV} & text { (3) } 4.5 mathrm{eV} text {} text {}end{array} )

(4). 5.eV

Solution

( begin{aligned} phi &=frac{h C}{7} &=frac{6 cdot 63 times 10^{-3} times 3 times 10^{8}}{250 times 10-9} &=frac{0.076 times 10^{-17}}{1.6 times 10^{19}} & approx 4.41 mathrm{eV} end{aligned} )