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If p is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having wavelength λ , then for 1.5 p 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)

1. λ 9 4
2. λ 3 2
3. λ 4 3
4. λ 2 1

Correct answer: λ 9 4

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