Class 12 NEET Physics Dual Nature of Matter and Radiation

Here,
Incident wave length,λ=200nm
Work function ϕ0=5.01eV
According to Einstein’s photoelectric equation
eVs=hυ−ϕ0
eVs=

hc

λ

−ϕ0
where Vs is the stopping potential
eVs=

(1240eVnm)

(200m)

−5.01eV
=6.2ev−5.01eV=1.2eV
Stopping potential, Vs=1.2V
The potential difference that must be applied to stop photoelectrons =−Vs=−1.2V