Question

in a photoelectric experiment, kinetic energy of photoelectron is 18.2 × 10^-19 J. the wavelength of incident light is X ×10^-8m , if work function of metal is 1eV, then value of X is ____.
(planks constant= 6.6×10^-34Js and 1eV =1.6×10^-19J)​

Answer 1

Answer:

Energy of incident radiation is E=

λ

hc

=

3×10

−7

6.6×10

−34

×3×10

8

=6.6×10

−19

J.

Also, work function is ϕ=2×1.6×10

−19

J=3.2×10

−19

J.

Hence, maximum kinetic energy of emitted photo electrons will be 6.6×10

−19

J−3.2×10

−19

J=3.4×10

−19

J.