MCQ
What is the energy of photon whose wavelength is $6840\,\mathop A\limits^o $ ?......$eV$
- ✓$1.81$
- B$3.6$
- C$-13.6$
- D$12.1$
✓
Answer
Correct option: A.
$1.81$
a
Energy of photon
Energy of photon
$E=\frac{h c}{\lambda}=\frac{6.6 \times 10^{-34} \times 3 \times 10^{8}}{6840 \times 10^{-10}}$
$=\frac{6.6 \times 3 \times 10^{-26}}{6.84 \times 10^{-7}}\, \mathrm{J}$
$=\frac{6.6 \times 3 \times 10^{-26}}{6.84 \times 10^{-7} \times 1.6 \times 10^{-19}}\, \mathrm{eV}=1.8 \,\mathrm{eV}$
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