Question

Which of the following phenomena cannot be explained by the wave theory of light?

• A. Reflection of light
• B. Diffraction of light
• C. Refraction of light
• D. Compton effect

Hint:

The Compton effect provides strong evidence for the particle nature of light, as it demonstrates energy and momentum transfer between photons and electrons.

Answer 1

The Correct Option is D

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 (photons) and cannot be explained by the wave theory. Instead, it is explained using quantum mechanics.

Answer 2

Step 1: Understanding the question.
We are asked which of the given phenomena cannot be explained by the wave theory of light.

Step 2: Recall phenomena explained by the wave theory.
The wave theory of light successfully explains the following phenomena:
- Interference
- Diffraction
- Polarization
- Reflection and Refraction

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

Step 3: Phenomena that require particle nature of light.
Certain phenomena, however, cannot be explained by wave theory and require the photon or particle model of light. These include:
- Photoelectric effect
- Compton effect
- Black body radiation

The Compton effect involves the scattering of X-rays by electrons, resulting in a shift in wavelength depending on the scattering angle. This can only be explained by treating light as consisting of particles (photons) that collide with electrons, transferring energy and momentum like in elastic collisions.

Step 4: Conclusion.
Since the Compton effect cannot be described using the wave theory of light, it is the correct answer.

Final Answer:
\[ \boxed{\text{Compton effect}} \]