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A beam of electromagnetic radiation of intensity 6.4 × 10 − 5 W / cm 2 is comprised of wavelength, λ = 310 n m . It falls normally on a metal (work function φ = 2 e V ) of surface area of 1 c m 2 . If one in 10 3 photons ejects an election, total number of electrons ejected in 1 s is 10 x . h c = 1240 e V n m , 1 e V = 1.6 × 10 - 19 J , then x is ___________

Correct answer

0

Step-by-step solution

Energy of photon. E = 1240 310   nm = 4 e V > 2 e V (So photoelectric effect will take place) = 4 × 1.6 × 10 - 19 = 6.4 × 10 - 19 j o u l e Number of photons falling per second = 6.4 × 10 - 5 × 1 6.4 × 10 - 19 = 10 14 Number of photoelectron emitted per second = 10 14 10 3 = 10 11

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