Question

In the experiment of photoelectric effect the
stopping potential corresponding to wavelength
4000A is obtained as 1.3 V. The work functior
of the metal will be
2.8 eV 2) 2.3 eV 3) 3.6 eV 4) 5.8 eV​

Answer 1

Answer :

2.3 ev

Solution :

eVS=hcλ−ϕ or eVS+ϕ0=hcλ

or λ=hceVS+ϕ0

⇒λ2λ1=eVS1+ϕ0eVS2+ϕ0

or 45004000=1.3+ϕ00.9+ϕ0

or ϕ0=851.−9.×0.9

Solving: ϕ0=(10.4−8.1)=2.3eV

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