K.E=E−Wλe=2mK⋅Eh,E=λihc,W=λ0hc2 mλe2 h2=λihc−λ0hcλe=2mc(λi1−λ01)h
JEE Main 2025 — Physics Modern Physics
A photo-emissive substance is illuminated with a radiation of wavelength λi so that it releases electrons with de-Broglie wavelength λe. The longest wavelength of radiation that can emit photoelectron is λ0. Expression for de-Broglie wavelength is given by :
( m: mass of the electron, h: Planck's constant and c : speed of light)
Held on 7 Apr 2025 · Verified 6 Jul 2026.
λe=2mc(λi1−λ01)h
λe=2mchλ0
λe=2mc(λi1−λ01)h
λe=2mchλi
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