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PhysicsModern PhysicsPhotoelectric effectEasy2 minPYQ_2020
PhysicsEasystatement

When the wavelength of radiation falling on a metal is changed from500nm to 200nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to:

Options:

Answer:
D
Solution:

KEmax=hcλ-ϕ=hc500-ϕ   .....(i)

Now,

3KEmax=hc200-ϕ

   .....(ii)

From equation (i) and (ii)

iii=31=hc200-ϕhc500-ϕ

Put the value of hc=1237.5 and solving ϕ=0.61eV

Stream:JEESubject:PhysicsTopic:Modern PhysicsSubtopic:Photoelectric effect
2mℹ️ Source: PYQ_2020

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