UPSC Prelims PYQ 2009: Which colour of visible light has the highest...

Which one among the following has the highest energy?

1. Blue light
2. Green light
3. Red light
4. Yellow light

Explanation

Option (a) is correct

• The wavelengths of visible light are:
  • Violet: 380–450 nm (688–789 THz frequency)
  • Blue: 450–495 nm
  • Green: 495–570 nm
  • Yellow: 570–590 nm
  • Orange: 590–620 nm
  • Red: 620–750 nm (400–484 THz frequency)

Answer: (a) Blue Light