NEET Questions Solved


The work function of a metal is 1.6×10-19 J. When the metal surface is illuminated by the light of wavelength 6400 Å, then the maximum kinetic energy of emitted photo-electrons will be
(Planck's constant = 6.4×10-34 Js
(a) 14×10-19 J                 (b) 2.8×10-19 J 
(c) 1.4×10-19 J                (d) 1.4×10-19 eV

(c) Kmax=hcλ-W0=6.4×10-34×3×1086400×10-10-1.6×10-19=1.4×10-19 J

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