Find the number of electrons emitted per second by a 24 W source of monochromatic light of wavelength 6600 mathringA, assuming 3 % efficiency for photoelectric effect (take h=6.6 × 10-34 Js )

Question

Find the number of electrons emitted per second by a 24 W source of monochromatic light of wavelength 6600 mathringA, assuming 3 % efficiency for photoelectric effect (take h=6.6 × 10-34 Js ) (A) 48 × 1019 (B) 48 × 1017 (C) 8 × 1019 (D) 24 × 1017

Tardigrade Admin · Accepted Answer

Energy per photon =h f or (h c/λ) Number of photon's per second =(24/h f) Number of electrons emitted =(3/100) × (24/h c) × λ

Q. Find the number of electrons emitted per second by a $24 W$ source of monochromatic light of wavelength $6600 \overset{˚}{A}$ , assuming $3%$ efficiency for photoelectric effect (take $h = 6.6 \times 1 0^{- 34} J s$ )

$48 \times 1 0^{19}$

$48 \times 1 0^{17}$

$8 \times 1 0^{19}$

$24 \times 1 0^{17}$

Energy per photon $= h f$ or $\frac{h c}{λ}$
Number of photon's per second $= \frac{24}{h f}$
Number of electrons emitted $= \frac{3}{100} \times \frac{24}{h c} \times λ$

Q. Find the number of electrons emitted per second by a 24W source of monochromatic light of wavelength 6600A˚, assuming 3% efficiency for photoelectric effect (take h=6.6×10−34Js )

48×1019

48×1017

8×1019

24×1017