MCQ
If the work function for a certain metal is $3.2 \times 10^{-19}$ joule and it is illuminated with light of frequency $8 \times 10^{14} \mathrm{~Hz}$. The maximum kinetic energy of the photo-electrons would be $\left(h=6.63 \times 10^{-34} \mathrm{Js}\right)$
  • $2.1 \times 10^{-19} \mathrm{~J}$
  • B
    $8.5 \times 10^{-19} J$
  • C
    $5.3 \times 10^{-19} \mathrm{~J}$
  • D
    $3.2 \times 10^{-19} \mathrm{~J}$

Answer

Correct option: A.
$2.1 \times 10^{-19} \mathrm{~J}$
$ K_{\max }=h v-W_0=6.6 \times 10^{-34} \times 8 \times 10^{14}-3.2 \times 10^{-19} $
$ =2.1 \times 10^{-19} \mathrm{~J}$

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