Arrange the following light rays in ascending order of their photon energy:
(A) Green
(B) Orange
(C) Violet
(D) Red
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (D), (B), (A), (C)
The energy of a photon is inversely proportional to its wavelength.
\( \displaystyle E = \frac{hc}{\lambda} \)
Approximate wavelengths in the visible spectrum:
\( \text{Red (D)}: \approx 700\,\mathrm{nm} \)
\( \text{Orange (B)}: \approx 610\,\mathrm{nm} \)
\( \text{Green (A)}: \approx 530\,\mathrm{nm} \)
\( \text{Violet (C)}: \approx 400\,\mathrm{nm} \)
The longest wavelength has the least energy, so the ascending order of photon energy is Red, Orange, Green, Violet, that is, (D), (B), (A), (C).