The frequency of a photon whose energy is 66.3 eV would be (Given \( h = 6.63 \times 10^{-34}\,\mathrm{J\,s} \))
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( 1.6 \times 10^{16}\,\mathrm{Hz} \)
The energy of a photon is \( E = h\nu \) (Planck's relation), so \( \nu = E/h \). The energy must first be converted from eV to joule.
\( \displaystyle E = 66.3\,\mathrm{eV} = 66.3 \times 1.6\times10^{-19}\,\mathrm{J} \)
\( \displaystyle \nu = \frac{E}{h} = \frac{66.3 \times 1.6\times10^{-19}}{6.63\times10^{-34}} = 10 \times 1.6\times10^{15} = 1.6\times10^{16}\,\mathrm{Hz} \)
Note: A similar question was also asked in CUET (UG) 2026 on 18-05-2026 (Slot 1).