Question

Light of which of the following colours will have the maximum energy in a photon associated with it?

• A. Red light
• B. Yellow light
• C. Green light
• D. Blue light

Hint:

In visible light: Red → lowest energy, Violet → highest energy. If violet is absent, choose the shortest wavelength colour available.

Answer 1

The Correct Option is D

Concept: Energy of a photon is given by Planck’s equation: \[ E = h\nu = \frac{hc}{\lambda} \] Where:

\( h \) = Planck’s constant
\( \nu \) = frequency
\( \lambda \) = wavelength
Thus:

Higher frequency \( \Rightarrow \) higher energy
Shorter wavelength \( \Rightarrow \) higher energy

Step 1: Compare visible light colours. In the visible spectrum:

Red → longest wavelength, lowest frequency
Yellow → shorter than red
Green → shorter than yellow
Blue → shortest wavelength among given options

Step 2: Determine maximum energy. Since energy is inversely proportional to wavelength: \[ E \propto \frac{1}{\lambda} \] The colour with the shortest wavelength has the maximum photon energy.
Step 3: Conclusion. Blue light has the highest frequency and hence maximum photon energy.