JEE Physics 2025 Question with Solution

Given: The options are Reflection of light, Diffraction of light, Refraction of light, and Compton effect.

Find: Which phenomenon cannot be explained by the wave theory of light.

The wave theory of light successfully explains phenomena such as:

• Reflection: wavefront bending at an interface.
• Refraction: change in speed and bending of light at different media.
• Diffraction: spreading of waves when they encounter obstacles.

However, the Compton effect involves the scattering of photons by electrons, which requires the particle nature of light and cannot be explained by the wave theory. It is explained using quantum mechanics.

Therefore, the correct option is D.

Given: We are asked which of the given phenomena cannot be explained by the wave theory of light.

Find: The phenomenon that requires the particle nature of light.

Step 1: Recall phenomena explained by the wave theory. The wave theory of light explains:

• Interference
• Diffraction
• Polarization
• Reflection and Refraction

These effects arise due to the wave nature of light, involving superposition and propagation of electromagnetic waves.

Step 2: Identify phenomena that require particle nature. Certain phenomena cannot be explained by wave theory and require the photon model of light. These include:

• Photoelectric effect
• Compton effect
• Black body radiation

Step 3: Apply this to the given options. Among the listed options, only Compton effect requires treating light as photons scattering from electrons with transfer of energy and momentum.

Conclusion: Since the Compton effect cannot be described using the wave theory of light, the correct option is D.