The wavelength of red light in the visible region is about 760 nm the energy of photon in that case will be:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 1.64 eV
The energy of a photon is \( E = h\nu = \frac{hc}{\lambda} \). Using \( \lambda = 760\,\mathrm{nm} = 760\times10^{-9}\,\mathrm{m} \):
\( \displaystyle E = \frac{6.63\times10^{-34}\times3\times10^{8}}{760\times10^{-9}}\,\mathrm{J} = 2.62\times10^{-19}\,\mathrm{J} \)
Converting with \( 1\,\mathrm{eV} = 1.6\times10^{-19}\,\mathrm{J} \):
\( \displaystyle E = \frac{2.62\times10^{-19}}{1.6\times10^{-19}}\,\mathrm{eV} \approx 1.64\,\mathrm{eV} \)