A photoelectric surface is illuminated successively by monochromatic light of wavelength λ and λ 2 . If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in t

Question

A photoelectric surface is illuminated successively by monochromatic light of wavelength $λ$ and $\frac{λ}{2}$ . If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is:
( $h$ = Planck's constant, $c$ = speed of light)NEET 2015 (Phase 2)

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Answer:

D

Solution:

$k_{1} = \frac{h c}{λ} - ψ$

$k_{2} = 3 k_{1} = \frac{2 h c}{λ} - ψ = \frac{3 h c}{λ} - 3 ψ$

So $2 ψ = \frac{h c}{λ}$ So $ψ = \frac{h c}{2 λ}$

TestHub · Accepted Answer

k 1 = h c λ - ψ k 2 = 3 k 1 = 2 h c λ - ψ = 3 h c λ - 3 ψ So 2 ψ = h c λ So ψ = h c 2 λ

Physics - Modern Physics Question with Solution | TestHub

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