hν−ϕ=KE
(λhc)incident=KE+ϕ
Given (ϕ<<KE)
(λhc)incident≈KE
(λhc)incident=2mp2 ......(i)
(λ′hc)=2m(1.5p)2 …….(ii)
Divide (i) and (ii)
λλ′=2.25p2p2
λ′=2.25λ×100=94
λ′=94λ
JEE Main 2019 — Chemistry Physical Chemistry
If p is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having wavelength λ, then for 1.5p momentum of the photoelectron, the wavelength of the light should be:
(Assume kinetic energy of ejected photoelectron to be very high in comparison to work function)
Held on 8 Apr 2019 · Verified 6 Jul 2026.
94λ
43λ
32λ
21λ
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